Women and relationships

Why is it that us women when we get into a relationship with someone 9/10 we get in too deep and end up being hurting the most.

Even celebrity women do this, like Girl's Aloud's Sarah Harding she had to even go to rehab because she took her break up with an ex boyfriend too hard and she started drinking and nearly committed suicide because the pain was too much to bear.

Why is it that us women we can't see when a relationship isn't really going anywhere, we think to ourselves that we can fix things and we can change the guy into what we want him to be, well sometimes that works but most of the times it doesn't.

There is a saying that says that when you improve a guy to be a better man you are most likely improving him into a man another woman is going to desire, be careful what you change your man into.