I have ASD as well and am too old and grumpy to bother masking these days

if people don't like it they can jog on.
Starters for Christmas dinner flummox me as well. I can't imagine filling up on bloody soup or pate or whatever when the most delicious meal of the year is waiting for me.
People who are really picky, demanding and ungrateful around presents. I don't mean the poor fuckers on here who are justifiably crestfallen that their DH has bought them a sickly candle from B&M. I mean people who actually look up prices of things and compare with what they've bought, or who have something incredibly specific and obscure in mind and then throw their toys out of the pram when a hapless relative gets it wrong. I devour those threads with ghoulish fascination every year.
I know one family where they all sit together and pick their presents out of the Argos catalogue. They are then duly ordered, wrapped and everyone pretends to be surprised and thrilled when they open them.
People who don't wrap presents give me the willies. I just can't wrap my head around it
People who have appalling, selfish, megalomaniacal relatives and run themselves ragged hosting them. I don't judge - I used to be in that situation myself, before I finally said "no" - but I do feel genuinely sympathetic towards those people who are still putting up with it (it's mainly women) and angry on their behalf.
People who don't do presents at all, while celebrating Christmas in every other respect, or people who do a family Secret Santa so everybody gets one small, crap present each. It wouldn't work for me at all.