I always say that I was the perfect parent before I had kids
This is sooo true. I was quite judgemental before I had kids. I think that is partly why I TRY to live by the standards I expected before I was a parent. Which is not easy, probably impossible. I find it interesting for my friends who have had kids 6-7 years after I did - there is a humbling that takes place in each of us parents. I try not to be so quick to judge. (But, the destructive thing really gets under my skin).
That humbling is the first step in realizing that bringing up kids is not about me in the short term, but about raising good and decent contributing members of society in the long run.
For me, it's a very vivid reminder of just how weak and flawed I am, but how much time and effort was invested into getting me even to this point!