I don't think it's just about formative years, it's more about emotional attachment in one way of another, even to songs that you first hear way past your formative years (although I think all years are formative, so let's say 'youth'). In June we gigged an album that I had listened to a few times and generally disliked, Beck's Odelay. It was a tricky one to play and we rehearsed it for around five months, about three months longer than it usually takes us to get an album down. I hadn't listened to it since, but I put in on yesterday and it felt like coming home in the same way as the music of my youth does, I heard all the magical nuances that I'd never noticed before we learned iit, and realised that the album had moved into 'that' space for me 👍