1) Sales Tax.
I know it's a thing, and in context of America's political system I understand to an extent why it's necessary. But it still catches me out. Every. Single. Time. I reactivated my phone today and was all ready to hand over the agreed money, when she slapped on over $2 extra in sales tax. I know in England there's 20% VAT included in most items, but sometimes I like to ignore how much of my money is going to the government. In America you can't escape that. Ever.
2) Sprite from fountain drink machines.
When I first came to America it took me nearly a week to realise that I wasn't just getting dodgy Sprite, it tasted different. And different meaning it tasted like laundry detergent. No wonder everyone says they prefer coke. But as soon as I get back on English soil all those memories fade away, and when I see Sprite written on a drinks machine Stateside again, it's never until the first gulp that everything unpleasant comes rushing back. Or maybe it's just a sign I need to stop going to fast food places.
3) Left side drives.
Mostly, the 'driving on the other side of the road' thing doesn't bother me so much, especially now I live in London. So many roads are one-way, that a car coming from either direction seems perfectly normal. However there was a magical moment earlier, when glancing at a car, I wondered what had happened to the steering wheel. Was this a crazy stunt? Part of a science fiction film set? A dramatic safety measure that my brain has no plausible explanation for? Even a self drive car?? No. It was just on the other side. As always.