I would argue the opposite. Kids are amazing. They see things clearer and arent jaded. They give you purpose. There are definately hard parts, and sometimes you dont get a break, but its not something I would trade for the world. They are little reflections of you, that you can improve on and watching someone with the wonder of awe of seeing and learning all these little things for the first time is pretty damn cool. Watching it "click" when they learn to do things like build stuff, ride a bike, swim, read etc etc is pretty awesome.