Understand: to perceive the meaning of; to grasp the reasonableness of.

Comprehend: to take in the significance, nature, or importance of.

It was a baffling thing for Sherlock Holmes to comprehend sometimes. 'Sometimes' because it depended on the context. If it was used by its primary definition – a view of or an attitude toward a situation or event; an opinion – Sherlock comprehended, even if the sentiments of other people were usually wrong. It was the secondary definition – a feeling or emotion – that Sherlock struggled with.

He understood it, of course. People had emotions. People felt things. He just didn't know why. There were times when he didn't know what they felt or when they felt it or what caused those feelings. He didn't comprehend, for example, why some people celebrated so enthusiastically the birth of a child – he understood that some people enjoyed the presence of babies and that they particularly liked the possession of one they could call their own, but he also understood that, with roughly 361,481 babies born a day, an individual child was hardly unique, and what's more, the world they were bringing them into was rarely pleasant. He did not comprehend the celebration that came along with a child, or the subsequent birthday celebration each year. It was one day, shared by 361,480+ others. He did not comprehend why one should celebrate being born. He'd once told John that it was actually the mother who should be celebrating, if anyone had a right to celebrate, but John had told him to shut up and eat his bagel.

He'd pondered the situation with the dog all night and could not put his finger on why it bothered him so much. It was a savage creature; the innkeepers had admitted as much. They should have had it put down and it irked him that they hadn't. The dog was dangerous; their reckless decision had nearly cost several lives the night before, and it definitely hadn't improved Henry Knight's sanity. Sherlock had thought it might; that was why he'd forced Henry to look at the corpse. What Sherlock hadn't expected was for it to affect him as well.

Why was it bothering him?

Sherlock brusquely tossed a shirt into his suitcase. (His mother would have been ashamed at the disorderliness of it.) It was an ugly dog. Not like his. Not like…

He paused as the memories returned, unwanted and unwelcome.

"He needs a friend, dear." That was his mother, whispering quietly over a late night cup of hot chocolate to his father as they sat reading by the fire. Sherlock huddled on the staircase, six-years-old and frightened by the storm outside. He'd already woken Mikey up. When he'd mentioned the East Wind, his big brother had mumbled something about anterior medial prefrontal and posterior cingulated cortices and unceremoniously flung a pillow at his head. So he'd crept downstairs, preparing his argument for why he should be allowed to wait out the storm with them even though it was past his bedtime. When he heard his name, though, he paused and listened.

"He has Mycroft," his father replied. He was probably reading mummy's book again. He read it all the time, but he never got any smarter.

"Mycroft is seven years older than Sherlock," mummy said. "The boys need friends their own age. It's important for them to socialize while they're young-"

"Are you reading psychology books again?" Sherlock suppressed a laugh. Mummy didn't like being interrupted; dad should have known better. He wasn't surprised when the next thing he heard was a sharp slap followed by an "Ow!" and a laugh from his father.

"That's not psychology; that's just common sense."

"The boys do fine out here."

"Sometimes I wonder if we should go back to the city; enroll them in real school."

"What do you mean 'real' school? They learn more from you than they would in a class with 25 other kids, kids who would hold them back and a teacher who would only give them some of the attention they need."

"There's no denying that they're smart; they're not social."

"What do you want to do, Violet? Drive them to the city for after-school football everyday? Mycroft won't play football."

"Mycroft won't play anything." Sherlock nodded in agreement with his mother's assessment. All Mycroft would play was chess and Operation, although sometimes, if Sherlock didn't distract him and he got all his work done early, Mikey would go outside with him and catch fireflies or play pirates in the river. Sherlock loved when Mikey did that. "We've tried with Mycroft; we haven't tried with Sherlock yet. We can't assume that just because Mycroft prefers to be alone that Sherlock does too. He's six – he should be playing, not reading all the time. I'm going to enroll him in a martial arts class. He has so much energy."

"Alright, dear." Sherlock heard his father stand up and he bolted up the stairs. Martial arts. He didn't know what that was, but he thought maybe he'd like it.

XXXXXX

Sherlock liked martial arts. He hated the other children.

Mikey had told him he would. "They'll think you're stupid," he'd assured Sherlock when he'd asked his brother what martial arts meant.

"I'm not stupid!"

"Yes, you are, but you're smarter than all of them."

"I don't understand…"

"I know." That was all Mikey would say before he went back to his book.

Sherlock had been so excited on the way to class. He'd looked up pictures of martial arts and he saw that people kicked and hit things. He was good at that.

The instructor made all the kids line up. Sherlock wasn't particularly patient, and he didn't like waiting, but he tried. When the man showed them how to do a kick, Sherlock had calmly raised his hand and asked what muscles were being used in the process. He'd asked again when they started punching. The other kids didn't seem to care; they just wanted to hit each other. And when they started practicing, they did it all wrong. They didn't do what the instructor told them, and when Sherlock tried to help, they told him to go away.

He didn't understand, and he didn't want to go back. He asked mummy to buy him a book about martial arts instead.

XXXXXX

It was a few weeks after the martial arts class that dad came home with a surprise. Mummy had put her hands over Sherlock's eyes and walked him outside. Mikey watched from the window. When she pulled her hands up, Sherlock stared at the giant, brown-red animal waiting beside his father in the grass. It was wagging its tail incessantly, pacing around on a leash, tongue lolling lazily from its mouth. When his father unhooked it, it bounded at Sherlock and knocked him over. His mother gasped and reached to pull the dog off of him, but Sherlock laughed and laughed as it licked his face. He clung to its neck and, when it straightened, it lifted him off the ground.

"He's all yours, Lock," his father said, smiling.

XXXXXX

It took Sherlock five days to name the dog. He'd wanted to get it right.

Mikey told him he was being dumb. "It's just a name," he'd said. "You can change it if you don't like it."

"No, you can't!" Sherlock had insisted.

"Don't be stupid, William," Mikey taunted. "It's just a name."

He settled on Redbeard. It was his favorite pirate, and the dog was sort of red too. When he told Mikey, he'd said he should name him Barbarossa, Redbeard's real name, but that was a mouthful to say.

"Fine, be simple," Mikey had said.

"It's just a name, remember?"

XXXXXX

Sherlock loved the dog from the very beginning. No longer did he have to wait for Mikey to finish his book; Redbeard was more than willing to wear a bandana and jump in the river with him. He was big enough that Sherlock could ride on his back, too; Mikey was too lazy to pick him up.

The next time the East Wind blew outside his window, he didn't crawl down the stairs because Redbeard was beside him, keeping him safe. When mummy made spinach, Redbeard waited patiently beneath the table for Sherlock to slip it to him. It was a mutually beneficial relationship.

When they moved closer to town a few years later, Sherlock sometimes took Redbeard to the park. They played fetch and ran around and when the other boys were there with their dogs, Sherlock sometimes pretended they were all playing together, even though he knew they weren't.

XXXXXX

He was eleven-years-old when Redbeard started sleeping more. He'd always been an energetic dog, could always keep up with Sherlock himself, but lately he'd been resting a lot, and moving slower when he moved at all. Sherlock went to the library (he had to tie Redbeard up outside – no dogs allowed) and asked the librarian for books about dogs. He politely told her that he meant real books, not baby books, when she walked with him to the children's section and then she just pointed in a different direction before returning to her desk. It only took him a few minutes to realize that Redbeard was sick.

Mike was only home from university for a few days, but he went with him to the veterinarian anyway; he even put Redbeard in his car without whining about it. After the vet told them it was cancer, his brother bought him an ice cream.

XXXXXX

"We think the most humane thing to do would be to put him down, Sherlock." His parents kept saying it, but Sherlock still shook his head. "He's suffering, sweetie. He can't play like he used to, you know that. If you love him, you'll let him go now."

Redbeard couldn't play, but he still put his head in Sherlock's lap while he did his homework. He still slept at his side when the storms came at night. Redbeard didn't want to die. And Sherlock wouldn't let him.

They told him that Redbeard ran away while he was at school. Sherlock wanted to believe them, so he did. Never mind the fact that Redbeard could barely walk anymore. Never mind that Redbeard would never leave him behind.

When Mike came home from university again, Sherlock told him what his parents had said. Mike laughed and said something about anterior medial prefrontal and posterior cingulated cortices. Sherlock didn't care, though. Redbeard was happier now, he was sure of that.

Wherever he was.

Sherlock understood, of course, now, that his parents had had Redbeard put down without his knowledge. It had to be without his knowledge, because he never would have allowed them to do it. Their arguments had made sense – he was in pain, he couldn't enjoy his life anymore, he was becoming too much of a burden and a distraction for Sherlock – but Sherlock had refused to listen to them. He'd loved that dog.

Sherlock paused on his way out the door. Sentiment. The innkeepers' decision was all due to sentiment. He thought about the dead dog again and realized: he wasn't bothered that they hadn't put their dog down, even though they should have; he was…upset that John had had to kill it.

The innkeepers loved their dog, as vicious and ugly as it was. Of course they couldn't put it down.

He did not understand the situation. But he comprehended it.

Classes are nearly done which means I get to start writing again. Like always, I own nothing, including the "comprehension vs understanding" concept - credit Joss Whedon and Firefly for that. Reviews are welcomed and appreciated.