Is learnt really a word or is it British English?
We Yanks don't speak (write) the Queen's English.

Neither do we Mediterranean types
You're kind of "surrounded by types", aren't you?
("What’s the difference between a cat and a comma? A cat has claws at the ends of its paws and a comma is a pause at the end of a clause.")

I've unknowingly been using the US forms of those "learned"/"burned" words when I "should" probably be using the British variants, but nobody told me ...