I completely identify with this article about parenting multiple children under the age of five.
The author calls it "The Tunnel of Parenthood".
Having three children under the age of six-- the oldest of whom is autistic-- has been a definite challenge.
Some day I know that I will look back and wonder how I did it.
Now I'm pregnant with Number Four. And this pregnancy has been so much easier because my two oldest are "past the hump" of total dependence. They can feed themselves somewhat, dress themselves, are toilet-trained, can amuse themselves and-- probably most importantly-- help me out. With my Number Three and with other chores.
I know that some people say that adolescence is also very difficult for parents. I don't buy it. It's not the same physical strain. And you can reason with an adolescent in a way that you can't a with a two-year-old. That's not to say that it's a piece of cake. But it doesn't require the constant on-call attention that dealing with toddlers often does.