Ne-Yo's "Do You" is relatable because we all have wondered at some point if our ex thinks about us from time to time. In the song he says, "Maybe this decision was a mistake. You probably don't care what I have to say/But it's been heavy on my mind for months now. Guess I'm trying to clear some mental space." Even though the relationship has come to a close, you start reminiscing on the good times, what went wrong in the relationship, and of course the "what if" moments.