“The man you are today is your memory of Eurus” 

  (Sherlock meta by thepurplecarbuncle and bassfanimation)

thepurplecarbuncle:

[...]  Absolutely not. Incorrect. How and why is that supposed to be true if he can’t even remember her? [...] You can’t make shit up as you go along and then pretend the random backstory you wrote into episode 13 has been some sort of unmentioned character arc from the beginning. [...]

bassfanimation:

It actually makes quite a lot of sense, especially if you take into account the series as an entire whole story. All of Sherlock’s choices make sense.

His preoccupation with solving murders = never being able to figure out what happened to his childhood best friend.

His temper tantrums and outbursts, failure to behave like a mature adult = childhood trauma at an early enough age that it essentially froze his emotional development.

His need for John = represents the best friend he lost, circling back around to Sherlock being essentially emotionally stunted at age 5 or 6.

His keeping all emotion and love away over cold hard logic = fear of loss, abandonment. Science and facts are always trustworthy and never leave you.

Mycroft’s preoccupation with Sherlock’s well being and safety = witnessing what loss did to his very small brother, and knowing it has damaged him terribly.

It’s understandable that many people didn’t like the character arc of Sherlock and don’t feel it was rolled out very well. It wasn’t done as well as it should have been, but I think the writers knew that getting everyone back together for a S5 was going to be virtually impossible. I do think they rushed forth with the Eurus storyline too quickly, and resolved it too quickly, I don’t think they had a choice.

Still, everything about it still made perfect sense, at least to me. I’ve had similar childhood trauma though, so maybe that’s why it feels so valid to me. I’m fully aware that I might be projecting, but the text of the storyline is really very clear to someone like me. It might be worth exploring along the lines of trauma though, and not so much about the cases or the villains, etc.