"So what happens to memories? In your mind palace I mean. You ever get lost in there? End up deleting stuff?"

"I'm always 'deleting stuff'," Sherlock replied, hands still steepled under his chin. "The useless stuff, at any rate."

"Yeah, but what about stuff you think is useless but that's actually pertinent to your relationships?" John asked. "Like for instance we are always out of milk, because you take about half a carton in your tea, but somehow, every Monday, there's another carton."

"Is this about me doing more of the grocery shopping?"

"It's a part of it," John nodded. "I am a single father, you know, I'm pretty busy with the clinic, and Rosie, and babysitting you."

"I don't need babysitting," Sherlock snapped, then glanced up, realizing his friend was teasing. He rolled his eyes, sitting up on the couch. "If you must know, yes, I do delete memories. The physical memory will be removed, but if it has an emotional context, that will remain."

"Such as?" John asked, curious.

"You suggested that I choose to forget that I use all the milk and don't replace it, which is a stupid example, because I know I'm using the milk, and as you are often out and about much more than I am, it seemed easier to let you continue to replace it. However if that has been an inconvenience, I shall endeavor to run to the shops more often. I sometimes forget that you have a good deal more to look after than yourself," Sherlock admitted.

"Okay, so my example was dumb, what do you mean?" John wanted to know.

Sherlock paused, thoughtful. "An emotional memory has a deeper impact. It's beyond me to remove them, and…in truth I do not want to."

"Such as?" John prodded, Rosie gurgled, and he bounced her gently, soothing her back.

"Such as what you're doing now, caring for Rosie," Sherlock said. "You're not simply my good friend anymore, John, you're a father. She won't remember you cradling her when she was this small, but she'll know the feelings you produce in her: a sense of comfort, strength, a sense of home," he paused, mind drifting off. "Every time she comes through the door, it'll feel safe again, as if nothing terrible could happen."

John was quite touched by Sherlock's application. It was no secret how much Sherlock loved Rosie. John appreciated his dearest friend opening up his home again to them. In this way, Rosie could be an even greater part of Sherlock's life. "Do you associate people with the emotional memories, the way Rosie will with me?" John wanted to know.

"Of course," Sherlock nodded.

"Like what? When?"

Sherlock shook his head, smiling to himself. There was always a particular memory that crept up, or at least the feelings behind that memory. "It's difficult to explain, isn't it, when it's only emotional context, feelings aren't always easy to explain. For whatever reason, I deleted the memory itself, but the feelings remained…I was…happy…very happy. I didn't know a body could be so happy thinking of someone, of seeing that person."

"Do memories ever come back?" John asked after a moment. Sherlock didn't answer for a moment, and when John looked up, he was surprised to see his friend had tears in his eyes, threatening to fall.

"No," Sherlock answered at last, finding his voice. "No they don't…flits of them do…small…pieces, but never the whole, and it is frustrating because I won't have that memory back, only the feeling."

"Well, it's a happy memory," John tried to console him. "Whatever it was. Maybe I can help. What do you remember?"

Sherlock took a breath, sighing. "It was April of 2011, or perhaps June, I don't remember exactly, just that it was warm. Crowded streets. I had to be there for a case. Mycroft's doing, that I remember. Massive parade."

John had on, what Molly affectionately called his 'thinking face', because his face scrunched up whenever he put facts together. "You mean the Royal Wedding?"

"I don't know, possibly," Sherlock waved his hand, annoyed. "There's was a good deal of color and music. I think I was holding someone's hand." He flexed his fingers, (a habit John had come to recognize as a memory tell, for Sherlock) then got to his feet.

"Crowds around Trafalgar were massive, you must've been completely packed in," John commented.

Sherlock was staring at the floor, retracing the bits of memory aloud: "I didn't mind…not the crowds or being so close. It was exhilarating, all the cheering, the fingers pressed together," he raised his eyes. "There was a pennant, caught in the breeze overhead. It was the same color…"

"Same color as what?"

Sherlock blinked, coming back to the present. "What?"

"You said there was a pennant, it was the same color as…" John gestured with his free hand. "Same color as what?"

"As my dress."

They both turned, surprised at the additional voice. There stood Molly Hooper, clutching the straps of her purse on her shoulder. She was looking at Sherlock. "Your brother wanted you to keep an eye on things, during the Royal Wedding, and you needed someone to go with you, to help you blend in. We got dressed up like everyone else in London did, and Mycroft got us close to the procession, so close you could've dodged between the guards and shook the Prince's hand if you wanted!"

John looked from Sherlock to Molly, then back again, shocked.

"We held hands, so we wouldn't be separated in the crush," Molly went on, quite unable to stop herself. "You were keeping a sharp eye, and told me to just enjoy myself, so I did. Wearing my silly white gloves and hat that I bought from Lock & Co. with your brother's charge card. You gave me a pennant to wave, so I wouldn't keep stealing your handkerchief," her smile reached her eyes, shining as she recalled the memory. "The wind kept on catching on my skirt, and you were annoyed that I was wearing a petticoat. As the carriages came round, the crowds all surged forward a little, and you caught me. I don't know what you said, there was too much shouting. We were separated for a little bit, only a little. I was standing on my tiptoes, and I finally saw you."

"Your dress was blue," Sherlock spoke at last, eyes round as saucers as he looked at Molly. "It was blue and white striped, and a sash that tied in the front."

Molly found herself blinking back tears. "I never said what color my dress was."

"You didn't have to," he said answered. "I remembered."

"I thought you couldn't remember things you deleted," John at last spoke, quiet, afraid to completely destroy the memory Molly and Sherlock were completely lost in.

Molly only glanced at John, then back to Sherlock. "There wasn't anything particularly…telling about that day…just that it was happy, it was just the two of us, nothing was said, nothing declared. There was just a mutual feeling, comfortable and happy. For the first time we were on the same page, and we didn't need to talk about it. It was just good to not think, to know and enjoy the moment. When you never mentioned it, I assumed you deleted it, because it wasn't important."

"It is important-" Sherlock rushed to speak, then cut himself short, gathering himself. "You are important. I didn't realize it at the time how important it was."

The tension was electrifying between them, as if there was cord that stretched and bent and twisted, giving way but never breaking. Quietly, John slipped out of the flat. Keenly, he wished for Mary, seeing the way Sherlock looked at Molly reminded him of the love he'd once shared with his wife, that impossible happiness that never lasted long enough. Molly only turned her head slightly as he went, tears filling her eyes as Sherlock continued:

"The parade traveled on, and the sun was in my eyes when I lost sight of you. Crowd of thousands, all shouting and waving, pure chaos. But I was certain I'd find you again, and I did." He closed the distance between them. "I'm sorry I forgot…"

"You didn't really," Molly answered. "You remembered the feelings."

"It's hell having the feelings but no memory to place them to," Sherlock murmured. Slipping his hands into hers, he laced his fingers between hers.

"Perhaps we should make new ones together," she suggested, stepping up flush against him.

"My sentiments exactly," he said before he dipped his head, finally kissing her.

Upstairs, John shut the door to his and Rosie's flat, smiling to himself. "Well Rosie, looks like you're going to be a flower girl after all," he kissed her forehead. "Between you and me, I think your mummy must have known a thing or two about your Auntie and Uncle long before anyone else did…" he picked up the package that had arrived in the mail. It had been sent from Mycroft along with a letter from Mary, instructing the elder Holmes to bloody do something about Sherlock and Molly. In the padded envelope were several pictures of Sherlock and Molly, the day of the Royal Wedding. The look in Sherlock's eyes as he regarded Molly, who was looking at the carriages, was unmistakable. The photograph may have been in black and white, but the feelings were not lost. John could envision both Sherlock and Molly at the front of the crowds, Molly cheering and waving, and Sherlock, quiet and still, keen eyes scanning the people around them, pausing every now and again to take in the sight of Molly, unable to stop himself from cataloging every detail about her. He supposed he could understand the feeling of a memory. Nobody forgets what it feels like to see a parade, it's exciting and happy. Nobody forgets what it feels like to realize someone makes you happy, completely happy, with no room for doubt, and you don't care what happens next, just that in the moment, nothing else matters, because the world is rosy and bright.

It took Sherlock six years to realize his source of happiness, funny how all it took was a pair of eyes, and a blue dress.