Don't sell yourself short. I feel the same way, and we have no children yet.
I prefer to think of it as wisdom from experience. As I told my wife of twenty years recently, "they look like children with big racks to me."
After the honeymoon, mine was damn near intolerable until she hit her mid-thirties. Who wants that again?
She's probably thinking something similar about you!
I hear that. The best years seem to be in front of me. I wouldn't want to go through the tough years again.