If it sang you might have been more certain (but I would have been more confused).
you are joking :lol:
Only a bit. I’m the kind of person who can’t sing happy birthday in tune. I don’t know if that has anything to do with it, but I can only remember a birdsong for about 3 minutes. There are some that I know every time: chaffinch, blackbird, raven (!), peregrine, skylark and a few others, but the majority just fade in my mind. The annoying thing is that I always say, “Ah yes, robin/wren/whatever, I’ll definitely know that next time I hear it”.