I was in Rome celebrating the New Year. I was 12 at the time. Italy still had Lira, not Euro. Found a note of 5000 Lira in the street. A 12 year old me went like 'Woah, I'm rich, baby!!!!' until our Italian guide told me that I can buy a single portion of ice cream with it. Just about.
The UK. First ever visit, second time abroad and haven't met many British people before. Was called 'love', 'darling' in the shops and I was perplexed (and a bit embarrassed 😆) until a local person explained that it's completely normal, they're just being friendly/polite and don't mean anything by it. Felt even MORE embarrassed then, as the person who explained it probs thought I have a massively overblown ego, thinking that every person in shops fancies me 😆I didn't really think that, it was just a bit odd to me.
The food (UK). Many things, but was genuinely amazed to see the weirdest carbs+carbs pairings, like crisps between breads, chips between breads, garlic bread with lasagna, etc. That was shocking (still is, tbh).
Sweden. Herring for breakfast. We also love herring where I come from, but eating it for breakfast would be considered extremely odd.
Someone upthread mentioned a unisex bathroom with transparent glass cubicles. I'm going to Prague for the first time in July and lots of (cheaper) hotels seem to have this on Booking. Booked one with a traditional, ensuite bathroom. Turns out, I'm a bit of a prude.
I don't find the Diana thing that weird, tbh. There were lots of celebrities' deaths with fans going hysterical. The recent one was that guy from One Direction, Liam something. Was in Cologne when he died and saw young teens and even some adults crying in the streets and the next day there were mini 'shrines' for him here and there. With photos, flowers, teddies and suchlike. Just and example, there were lots of others. Michael Jackson, etc. Sure, Diana wasn't a singer, but she was incomparably more famous and 'bigger' than the One Direction guy.