Dress and Tie

“But how can other people tell who you are on the inside? How can they see?”
“They can’t, Sherlock, that’s the point.”
“Well, then they shouldn’t be allowed to tell you what you are. It’s stupid, it doesn’t make any sense.”
Sherlock knows a lot of things. He knows where plants get their green colour from, what the first element on the periodic table is, that DNA is the shortened form of the term deoxyribonucleic acid, how long it usually takes his mould cultures to grow to a respectable size and that Mycroft is his brother. He doesn't understand why people keep disagreeing with that last one, though.