OKAY BUT THINK ABOUT THIS:
So Sherlock has all this information stored in his head and sometimes it gets too full - which is why he has to delete things…so now that he loves lives with John, he keeps saving all these things about John. Like the way he laughs and all the ways John’s told Sherlock that he’s amazing and brilliant and wonderful and the way his hair smells and the way he walks and talks and- (ANYWAYS) one day his “computer” gets too full.
So Sherlock should do the sensible thing and just get rid of some of the stuff about John (seriously, when is he ever gonna need the exact way John walks)…bUT HE DOESN’T. HE FREAKING GETS RID OF SOMETHING ELSE. SOMETHING THAT COULD POTENTIALLY BE IMPORTANT. SO he’s like “lol when am I ever gonna need all of this stars and planets junk????”
D O Y O U S E E W H A T I ‘ M G E T T I N G A T H E R E ?