He has a notebook for EVERYTHINGGG. Not just hero analysis, but also things like note-taking, doodling, scrapbooking, journalling, you name it, he's got it.
◇ He's also got a concerning amount of blank notebooks, cos he finishes them FAST. In fact, he's the only person who dedicates themselves to actually finishing their notebooks rather than getting excited by seeing one with a pretty cover in a stationery shop, writing one page in it, then forgetting it even exists the next day. Also, if his classmates want notebooks, he's got them covered... probably for the rest of their lives.
◇ He's kept all his notebooks from childhood till present. Even the ones from when he first learnt to write. He thinks it's a good way of tracking his growth and how far he's come. His mum tried to convince him there's no point in keeping them, but he's rlly attached to all his notebooks and can't bear to throw them away.
2. He has a collection of little, meaningful things that ppl gave him or from diff events. As in, the sweet note you passed to him in class? He still has it. That roll of photos you printed from the photos booth on the day everyone went shopping? He still has it. Wristbands from the School Festival or concerts he went to w his friends? He still has them. The letters Eri writes him? He's got a whole separate folder just for them. Little things like that mean a LOT to him.
3. When he learns to drive, he becomes the most RECKLESS driver ever. As in, he'll try to be careful, but it'll fail miserably cos he's not focusing, OR he'll just make crazy impulsive decisions like the kind of sudden turns that make the tires skid on the road.
◇ He's almost always late to work, cos his schedule becomes so busy. Hence the rushing and impulsive decisions 😅
Aizawa: (disappointed nod) Midoriya. Late again...
Deku: Sorry, Sensei! I got caught up in a few things... and I mean, we're not in class anymore. I'm all grown up!
Aizawa: Doesn't feel that way sometimes.
4. He's a night owl. Almost every night, he'll be up till 4AM studying, writing in his notebook, or exercising. And cos he's so used to it, he doesn't feel that tired even after getting only 2 hours of sleep. In fact, he'll get tired when he gets MORE hours of sleep than that. His classmates (especially Iida) will force him to go to sleep early, but...
Iida: (chopping the air) Midoriya!! I've been told you haven't been sleeping!!!
Deku: (taken aback) I-It's not that! I just—
Iida: I don't want any arguments! You are going to bed RIGHT THIS INSTANT— (grabs Deku's hand and drags him up to his dorm)
Deku: B-BUT— okay fine...
(He then proceeds to stay up regardless. We all know how stubborn he is.)