Hi Jane! Thanks for sharing your experience. I always marvel at how we humans stumble our way through parenting. My eldest likes to complain we were far stricter with her when she was a young child than her younger sister and I always point out that we didn't know any better.
I think there's a lot of truth to that observation that youngest kids getting "broken-in" parents! It makes me wonder if some eldest boys are treated more strictly than some eldest girls, since new parents may not know how to channel that excess energy except through time-outs/discipline.