For Mature Men Only, Please?

Given this hypothetical situation, what are your feelings. You have fathered a child. The mother leaves you, taking the child with her. She has totally cut you off from her and your child. You were a responsible father, she left for her own selfish reasons. Father's Day is here. You see other parents with their children. What are your musings upon seeing other fathers being given the opportunity to excercise their paternal instincts.

I understand that this may not be a hypothetical situation for many, I would especially appreciate your responses. Your responses will be incorporated into a character that is being developed for a piece of fiction.