What people don’t realize is that Sherlock is constantly mocked and bullied. His flatmates meet him, realize he’s hard to be around and leave. He doesn’t have any friends, his own brother only seems to care for him because he’s family and might cause a bad image, but otherwise doesn’t give a flying fuck about him.
At work, he’s called ‘freak’ and his deductions are doubted even after they’ve seen hundreds of solved cases under his reign. Lestrade is only his friend because he’s useful, he calls Sherlock a right git and doesn’t do anything to stop Donovan or Anderson from mocking him and making his job harder.
Ms.Hudson is his landlady, the second person who doesn’t show outright care for him, but to a mind like Sherlock, he assumes it’s because she feels indebted to him. It doesn’t make sense for her to actually care about him, he’s ‘heartless’ and ‘freakish’ to everyone around him so why would a sweet old lady care about him?
Above all, Sherlock is utterly lonely. He’s got his experiments, he’s got his work, where he’s bullied and mocked so much that he promptly ignores and then he has the occasional flatmate that try to befriend him and suddenly stop caring when they’ve had enough.
And then there’s John Watson. Sherlock expects him to leave, that’s why in the beginning, he’s more charming then usual, winking at him when he leaves, smiling when they go to check out 221b and getting reservations for dinner. After the drugs bust, Sherlock is sure John will leave— not even Mycroft cared when he found out about the addiction and at least part of Sherlock is craving attention.
Sherlock is probably the most lonely person on the show. Not John, the quiet blogger. Not Lestrade, the man invested in work when it’s his division. Not Ms.Hudson in her quiet dusting and “Not your housekeeper”s. Not even Molly with her silent wanting for Sherlock. Finding John was probably the best thing that could happen to him.
