I have this head-canon that Mycroft was really mean to Sherlock as a kid and that Mycroft used to be hooked on drugs and Sherlock wanted to be like his brother so he started doing drugs but couldn't get off of them like Mycroft did and Sherlock got all fucked-up trying to be just like his older brother and hated Mycroft for it and Mycroft felt really bad and never told Sherlock he was sorry for being such an enormous dick and instead just stayed out of Sherlock's way while still watching him from afar because he was worried about Sherlock getting all f'ed up again.
In case anyone was wondering why Mycroft is the queen of Dicktopia in my recent fanfiction.











