11 painful things:

1) bringing back the feeling you've learned to forget 
2) reminiscing the good times 
3) trying to hide your true feelings
4) loving someone who loves another 
5) having a commitment with someone you know would not last 
6) right love wrong time 
7) loving someone more then they love you 
8)putting all the effort in and they don't bother 
9) taking risk to love someone again 
10) accepting they don't like you in that way and you're stuck in the friend zone
11) accepting that you can't make someone happy.