Kids are expensive. They are amazing, and expensive. Expensive enough that all the [somewhat flawed] posts about how, if you start saving 15% of your income when you're 25 you'll have somewhere in the neighborhood of several millions of dollars when you retire--well, all that can kind of fly out the window if you're 30- or 40-something and finding it hard to save because of summer camps, and clothes, and food for a middle-school boy, and sports teams, and college tuition. So then you read all those other posts about how there's such a large retirement savings gap in the US, and then feel deflated and resigned to the fact that you'll be sitting at work for at least fifty more years.