Why?

Why is it that children have all the energy in the world, and parents are constantly exhausted? All the children have to do is play. Parents have to have the energy to work all day. Shouldn't it be the other way around?

Why is it that when you can finally go to bed when you want to that you get insomnia? When I was a young mother I could have gone to sleep at the drop of a hat, now that I can go to bed, I can't sleep.

Why is it that even though you promised you would never do the same things your parents did, that you actually end up doing the same things your parents did?