Somehow around the birthdays, my kids tend to demonstrate an adherence to this idea. Magically, just 2 weeks after his birthday, Theo's behaviors are driving me CRAZY.
Enter a good developmental chart. I learned as a very early parent that if my baby's behavior was on "the chart" I could relax. See now instead of my wee one doing some scary freaky thing, he is just really doing a great job of being a 6 month old. Same holds with the 8 year old and charts. It is just that there are more freaky behaviors.
Scientists love babies and there are more developmental charts than you can throw a diaper at. But clear 3 years old and pickings get slim. I was stuck with merely the Ilg/Ames selection for years. Which admittedly are better than nothing, but much of the parenting advice rubs me the wrong way. Happily I stumbled upon the Washington State DSHS charts last year. The charts go from 0-19 years, with sections for physical, intellectual, emotional, social and moral development. Appropriate milestones are marked with short and reasonable suggestions for how to handle behaviors. I print them out and post them in the kitchen where I can see them daily.
Now if I can just convince myself he's great at being 8 years old and that those thunderous burps aren't really SO annoying.