Nah, here in Germany for example, the standard single bed is 90x200cm, the standard double bed is 140x200cm and the king size (although I’m not sure how it would actually be called) is 180x200cm and usually just uses two 90x200cm mattresses. Can’t say I’ve ever seen a larger bed.
Because the college would tell you the dorm rooms have twin mattresses in them. So everybody shows up with twin sized sheets.
You can actually get fitted twin sized sheets to fit a twin-xl mattress if you fold the mattress a little when you put on the sheet.. When the mattress straightens out it compresses a little, and the sheets stretch a little. But you'll also find the weak spots in your sheets very fast.
When my husband and i started dating we slept together in a twin. Now we sleep in a king with 2-3 cats, and a dog if there's a storm. Sometimes on vacation we have a room with a queen. Makes you realize how much space the animals take.