I know of both circumstances too... mother or father up and leaving and no contact

personally i dont know how they do it

my ex thought the grass was going to be greener on the other side of the fence and well I sit here and laugh at him because he is miserable and alone because he thought he would have no problems in the single world and women would flock to him (kid me not)

and as for me I am happier then i have been in a long time (nothing but the girls births has made me happier) I am in a wonderful relationship with the most gorgeous man..

and as for the contact.. sometimes i would have preferred he walked away and never looked back, because in my eyes it would be easier to deal with then his half arsed parenting which only happens because his family dictate to him that he needs to see the girls and they would be extremly disappointed if he stopped contact.. so really he only sees them because he thinks it the right thing not because he wants too. and well 90% of the time the girls would rather stay home with me.. which makes it sader.