Sheldon was at a loss for words. After twenty-six years of being in a relationship with Amy, he knew how to read her emotions. He knew the difference between surprise and disappointment. He understood why one, particularly a female, would be crying for the sole reason of there being a lack of French vanilla ice cream. But no matter how adept he had become at reading Amy, he was a terrific failure at reading their sixteen-year-old daughter.

When he was faced with situations such as these in the past, he would tell himself that he simply did not care enough about the other person to decode their body language and facial expressions. But that obviously wasn't the case with Mia. He loved her very dearly. He was willing to put in the extra effort to understand why she was feeling blue, but she refused to meet him halfway. She just sprawled out on the couch under a blanket, poring over some new historical fiction novel. Sometimes Sheldon thought that all of Mia's moodiness could be contributed to the fact that she was obsessed with the humanities.

"I just don't understand, Amy," he complained one night as he placed plates and napkins around the dining room table. He paused in thought and crossed his arms over his chest. "What's wrong with her?" he exclaimed, dropping his hands in frustration.

Amy laughed and continued preparing the dinner salad.

Sheldon crossed the kitchen and stood by her side. "I'm serious!" he said, handing her a bag of baby carrots from the other counter. "I really think we need to get her medically diagnosed or something."

"She's not ill, Sheldon, she's just a normal teenage girl doing normal teenage girl things," she explained, tossing the vegetables in a wooden bowl.

"Oh, please, Amy, you know she's far too intelligent to be considered a 'normal' teenage girl," he rebutted, a proud smirk plastered across his face.

Amy found three sets of forks and spoons from the drawer and handed them to her husband. "Sheldon, you can't use an excess of intelligence to balance hormones. Can you put those on the table, please?"

He sighed, but did as he was told. "I beg to differ, Amy. One word. Kolinahr."

Amy grabbed the bowl and placed it on the table as Sheldon set the silverware. "I really don't think Mia wishes to participate in the purging of all emotions," she countered. "And I have two words for you. Menstrual. Cycle," she said, patting him on the stomach before she returned to the kitchen.

Sheldon straightened up upon hearing Amy's implication. "Hmm. I did not consider that," he said, cocking his head the left. "Do you really think that's the reason she's acting like this?" he asked, rejoining her in the kitchen.

"No, Sheldon, I think she deliberately chooses to become a hermit for exactly six days each month," she answered, pulling her head out of the oven.

Sheldon took the glasses from her face and wiped the fog off of them. "It occurs to me that you may have been using sarcasm, and I'm not satisfied with your inference that it should have been obvious to me," he said, gently returning the lenses to her face.

"Sheldon, for someone who's so schedule-oriented, I really thought it would be," she replied. "Besides, you always knew when I started mine. You were more torn up about menopause than I was," she teased.

"Hey, if you're correct, and Mia is really retreating to her historical 'red tent', then she acts nothing like you did in similar circumstances," he accused, grabbing the tray of baked chicken and heading again towards the table.

"Oh, pray tell," she sarcastically quipped.

He didn't notice the mockery in her tone. "Okay," he started, sitting in his spot. "When you were on your period, all you wanted to do was cuddle like a couple of hippies. Mia won't even come near me. You hardly ate anything but ice cream all week. Mia hardly eats anything at all. You cried approximately every thirty-six hours. Mia hasn't showed the slightest bit of emotion in three days. Now you tell me how I was supposed to know."

Amy chuckled and took her seat next to him. "Mia, dinner!" she called out into the living room before turning her attention back to Sheldon. "Hey, maybe she is practicing Kolinahr after all," she said.

Mia wordlessly rounded the corner and began picking at her meal. It all suddenly made sense to Sheldon. He shared an understanding gaze with Amy before returning his attention to the bowl of salad in front of him.

Amy passed a bottle to him. "Care for some raspberry vinaigrette with that?" she suggested with a smirk on her face.

He glared at her and she raised her eyebrows at him in return. "Thank you, but I'll pass," he answered, an identical smirk slowly starting to engulf his countenance.

Mia lowered the water glass from her lips and placed it on the coaster. "What, did I miss something?"

"Nope," said Sheldon, taking a bite of his salad. "You most certainly did not."