What songs (hopefully major) do you remember where you were when you first heard them?

Myself, just two: Bob Dylan's version of Mr. Tambourine Man. It was maybe 3AM, and in order not to disturb others in the house I put on headphones and listened to Bringing it All Back Home. When I came to that song it was just magic. Stones' Satisfaction. I was standing in my bathroom listening to a local radio station and thought to myself, that's a song that's going to get overplayed on the radio for sure. Which, of course, happened from the get go.