[Error: unknown template qotd]Oh God, you can do a lot with hindsight, can't you? Dealing with a truly-broken heart is a very painful process. I suppose it depends on how badly it ended, especially if you had both invested a lot of time and energy in the relationship.
I have a feeling that if I knew that things were going to end badly, I would steer clear of the relationship and indeed have done so in the past.