oh my lord why are you doing this to me??? because
sirius never turning in homework on time during school simply because he kept messing up with the quill and he can’t have crossed out words or ink blots on his parchment. After restarting 5 times, he gives up and cries in the common room at 2 am, all alone with his crumpled parchment.
Sirius living with intrusive thoughts that he sometimes gives into, doing reckless things after battling the urge for hours on end and being yelled at for being “careless”
Sirius being driven CRAZY by james’ messy hair, but refusing to bring it up
Generally overcompensating, acting like nothing bothers him because Sirius has been taught that acting out or seeming odd results in punishment.
Sirius hiding all his valuables in a locked box due to fear of his things being looked through or stolen, left over from his time at the Black house. He checks the lock exactly 27 times, without fail, every morning and every evening, as well as anytime he removes anything from the box. There’s no reason for the number.
Sirius needing to be perfectly rumpled, afraid people will stop liking him if he doesn’t appear a certain way. asking the other marauders several times in a row if he looks “good” or “cool enough”, and still fearing that he looks wrong somehow, that he’s gonna lose everyone because he appeared wrong.
God you give good headcanons. Please talk to me more about marauders??