I saw a video clip from, sheesh 80, 81, (Adam had the fro), and while Bono was speaking to an interviewer, Adam was sitting next to Bono listening to him, while gently twiddling an earring in his ear.
I got my ears pierced when I was very young, but I haven't worn earrings since I was 8 or 9. The piercings have since closed up, and I haven't gotten them redone. I just don't bother with earrings, or I get nice looking clipons. I also work with animals so it's best that I not have them anyhow.