Here’s an interesting round-up of everything JK Rowling has said about Albus Dumbledore:
Dumbledore has a scar on his left knee which is a “perfect map of the London underground.
‘Dumbledore’ is “old English word meaning bumblebee. Because Albus Dumbledore is very fond of music, I always imagined him as sort of humming to himself a lot.”# [...]