This description comes from non-parent, Tim Kreider, but he clearly has an enormous capacity for empathy, and so explains it perfectly:
"Most of my married friends now have children, the rewards of which appear to be exclusively intangible and, like the mysteries of some gnostic sect, incommunicable to outsiders. It's as if these people have joined a cult: they claim to be happier and more fulfilled than ever before even though they live in conditions of appalling filth and degradation, deprived of the most basic freedoms and dignity, and owe unquestioning obedience to a pampered sociopath master whose every whim is law. (Note to friends with children: I am referring only to other people's children, not yours.) They're frantic and haggard and constantly exhausted, getting through the days on a sleep deficit of three years, complaining about how busy and circumscribed their lives are, as though they hadn't freely chosen it all."
From the essay "The Referendum," from his book "We Learn Nothing." I could not possibly recommend the book strongly enough, and a big thanksmom! for getting it for me.