[TexasFreeper2009]

then they failed at parenting.

There is a saying in my family, that you dont know how good of a parent you were until you see how you grandchildren turned out.

For if the lessons you taught your children they chose not to pass on, then you failed.

[equaviator]

"you dont know how good of a parent you were until you see how you grandchildren turned out."

The catch is that you have to live long enough to see how your grandchildren turned out.

[Secret Agent Man]

Not always an accurate measurement.

The grandparents could have been fine, but raised crappy kids, but the grandkids, despite their crappy parents, decided to do the opposite of the parents and learned proper things by not being like their parents.