Sometimes we marry the wrong person. Maybe s/he is a good person, but s/he is not the right companion for us - at all.

Once we realize this, and there are child(ren) involved, we have to choose between:

1. A unhappy marriage where two unhappy parents live together.

2. Two divorced and somehow happier parents who live apart, but who (hopefully) cooperate on parenting.

Research suggests than situation no. 2 is usually better for the child(ren) too (and I think DPM agrees). Being raised in an unhappy environment primes one to live in an unhappy way.