When I was a late teen, it was "I Still Haven't Found What I'm Looking For", by U2. However, though I still like it, I have found what I'm looking for, so it has less meaning for me now. Really I like many songs from those decades. Hard to choose. Maybe... a few from Queen are strong contenders, like "We Are The Champions", "Bicycle", and of course "Bohemian Rhapsody".

What is a significant way you've changed since childhood?