i have a LOT of quirks, so ill give you a small selection
when i eat fruit pastilles, i have to pour the bag onto a plate, separate them all into colour piles working with the colours of the rainbow going clockwise. none of the piles can touch, then i eat the sections down until they have the same number, then go anticlockwise taking one off each pile until i have only three of each type left, then i eat all three individually of each colour backwards until i have red, orange and yellow left, at which point i will eat one more off each pile, then eat the last two as a pair, so both yellow, both orange, then both reds. I have food issues they just dont taste as good any other way!
i only have one specific pair of shoes i can drive in - if i dont have those shoes with me i have to drive barefoot. This is because i get foot cramp and my leg feels funny otherwise, even if other shoes actually fit me better.... i did buy an identical pair of shoes to wear to drive, but they just dont feel the same.
i concentrate better with my back directly pressed against a wall and sitting facing the door, than i do in any other position
i regularly rewrite the family shopping list (no joke, about 4 times a week and we shop once a week...) to make sure that all items are in the correct category (so split into vegetables, fridge, cupboards, freezer, and household). I could also give you a full list of everything that we have in our kitchen, food wise... this started happening after sister took control of the shopping list and we ended up with about 5kg of red onions and no potatoes