well for me, i am friends with most of my exes. it depends on who broke up with who and why. also it depends on ur memories together is it too hard to face them? etc. for me though, those memories i shared with my exes will always be special to me no matter what happened towards the end... which is why i can be friends with them, because those times you shared together is like a bond that ties you both together. (although in some cases there is no bond.. like if (s)he cheated on your or something)