Note: this seems like it only applies if you're putting your children into a school. If you're homeschooling that "free time" doesn't materialize. It also doesn't happen if you have two children (or more) a couple of years apart, as their school start and end times won't sync up except a few times over the course of > decade.

I had a friend gently remind me that the reason he can be prolific at writing music these days and i "can't seem to find the time" is because i've raised 2 and currently am raising a third, and if he had kids he wouldn't write music either. My youngest turned 7 this year. Older two are out of the house.