Three things combined in my case.

I was a reasonable recorder player at primary school, but rapidly lost interest at secondary school through the quasi-military and relentlessly classically-orientated teaching. However when my younger sister started learning to play (to a very high standard I might add) I reacquainted myself with one of her cast-off recorders when I was about 15 or 16, and quickly also acquired a tin whistle.

I was also exploring the further reaches of the Southend Central Library LP collection with a couple of school-friends; we were discovering stuff like The Albion Band, Fairport, and Steeleye Span, Planxty, The Bothy Band, and all sorts of other less-well-known but excellent stuff [and David Munrow and Renaissance music as well] - so I owe a great debt of thanks to those friends and also to whoever that fine Music Librarian was. Crucially some of these records featured wonderful music made on the very instruments I was in the process of learning to play, giving me both a repertoire and an immediate way in.

And thirdly, I was doing a Saturday job where most of the other people were in a ceilidh band together, so I got an early insight into both the joy of playing for dancing, and the whole social side of the music.

Combine those three and very quickly indeed, to mix Pip Radish's metaphor, the furnace door flew open and welcomed me in with open arms!