Parents and Self Pity

This is an interesting fact but true for most of the parents.We always feel and are absolutely sure that we have not got a decent deal as parents.
Our siblings have better kids who are academically smart,good at games ... the list is endless.

Do we ever look into ourselves and realize that our kids are manifestations of our deeds and thoughts.May be we did not hope hard enough for them to succeed How do we measure success? Is success not relative term? Isn't happiness more important?