Men give a multitude of reasons why they are unhappy in a relationship - but usually this just means they are confused themselves. They are having trouble sorting out their own feelings.
This is good if you want to know how to win my ex boyfriend back - it means that if you do and say the right things, you can easily win him back. If you do the wrong things, however, then that will help him clarify his decision to leave you.
So what can you do to win back an ex boyfriend?
1) Show him how much you admire him
Studies have shown that men leave women when they no longer feel admired. He generally reads this by how happy his woman is around him. If you nag him or are less than happy when he comes home, then he won't be happy himself.
Then the next time another woman, say from work, shows him attention, he's going to lap it up. This is the primary reason men cheat. It can easily be avoided by showing him how much he means to you every now and then.
2) Attract him back
It has also been proven that the best way to win your ex boyfriend back is by attraction, as opposed to persuasion. Don't go to him - let him come to you. Show what a strong, independent person you are. Some people suggest dating or flirting with other men. This will depend on your situation, but it can certainly arouse desire in your ex boyfriend. Nothing will spark him into action more than the thought that he might lose you forever.
3) Pinpoint the problem
In the end, the only way to win back your man is to change whatever hasn't been working so far. You can't expect a long term relationship if either of you is unhappy. Sometimes this involves sacrifice, but it's worth it in the end.