Any last words?

The other day I was on the phone with someone, and I noticed something that I do. I don't know why I do it, and I don't try, but it just happens. Whenever the conversation comes to an end, I always have to be the last one to say goodbye. I really honestly don't know why, but it feels wrong to me if I don't. I'll even wait an awkward amount of time in silence for the other person to say bye first. It's really weird. Because I noticed it, I try hard not to do it, and I've done pretty good. But still, every time I do it, I feel like I'm cutting the other person off halfway through a sentence or something, even if I'm not. I am a strange person.