Ooooooh 12 is headcanons...
Brain talks through the movie. He has always seen this movie before you, and he always knows all the trivia, and he cannot stop telling you about it. Do not try to see a movie for the first time with Brain.
Was rude to the waitstaff exactly ONE TIME, after which Heart looked quietly upset. This is why he only did it once, Heart's reactions absolutely shift Brain's behavior.
Will 'he asked for no pickles' for Heart. (Medic also does this, they team up on occasion)
Thinks human sexuality is frankly disgusting. Would not think of himself via a human sexuality, but I hc him as sex repulsed asexual with a very complicated sometimes-exception for Heart.
I just sort of assume he's connected to the internet whenever he wants to be, and he has zero caution for weird sketchy websites. His OS is so foreign that no virus can actually affect him, so he just collects them inside of himself until they start taking up too much space. Then he offloads them into some other machine's data storage center. He is not allowed to do this to civilian computers/tablets/et al, which I think he thinks is really inconvenient.
