To convince (v.):

1. to move by argument or evidence to belief.
2. to persuade; cajole.

I don't need you to pay attention to me to know that I'm eye-catching. I don't care that you'll only approach me in private, because I know that I'm worth showing off, and that you're missing out. It doesn't matter if you're smiling with another girl, because I can still laugh with or without you there. I'm not going to give you a second look, because I'm not going to be there at your disposal. I don't have to let you in. I don't have to take you back.
I don't have to tell myself these things. But maybe if I do... one day I'll actually believe them with everything I have.