Well, some of that is idiosyncratic, but in a nutshell, I would worry far LESS about "should/should not" and far more about the child that I was actually seeing in front of me.
I shot myself in the foot on a number of occasions by NOT responding to my child's desire to do/learn/try something because developmentally she "shouldn't/couldn't" really be ready. Toilet training at 11-14 months? No way. Too early. (Problem was she was a WHOLE lot less cooperative at age 2, I'll tell ya...)
Wants reading instruction at 18 months? Are you crazy? Leave that push parenting for the whack jobs-- just "enjoy" your child and play with play do and finger paint with her instead (well, not PlayDo, since she was allergic to wheat, but anyway...)
I also spent a lot of time trying to find a preschool setting that could work for her, and that was an absolutely STUPID waste of time-- and it was a lot of time. I should have been looking for a piano teacher who would give her a trial instead, and teaching her to read when she was BURNING to learn.
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I would be a WHOLE lot less invested in being normative, in other words. I forced my child to be a 'baby' in ways that she found appalling and felt unable to communicate to me/us. I look back and recall her coming home from "toddler" music class and giving me this reproachful look and asking to take a nap 'with it quiet.' It was a lot of things like that.
