Nothing can prepare you for the "crap I can't do anything spontaneous now" like having children. I recently had to let tickets to a concert go (that I was really looking forward to) because the babysitter had a family emergency.
And this is a deep confession that I've never really told anyone: I envy my divorced friends with kids. Every other week they (usually) are child free. And get to do things like mow grass, have a dinner with an SO at a place that doesn't have a built-in playground, or go on weekend trips on a whim. That guaranteed time without children that you get from custody agreements has a ton of perks. I won't admit this out loud, though.
You should give it a try, my wife and I get occasional nights and weekends off, its pretty nice. Also we live in an area with an active city parks and rec, and we have a childless date night with each other this very Friday night, I don't even know what parks and rec class my wife signed the kids up for (probably the fall kickball tournament, the Halloween party is next month). We also send them to day camps a couple times each summer so we have some married adult time while the kids are theoretically getting exercised, educated, and socialized.
My experience is "For profit" camps tend to charge what the market will bear ($$$$$) and always have openings. Parks and rec charge what it actually costs to provide the activity (maybe $20/day/kid?) but reservation slots fill up fast every year.
What you're describing and what the parent described seems very different to me. Not only does "every other week off" vs "occasional nights and weekends off" have an obvious quantitative difference, it has a very strong qualitative difference.
1 day off to every 5 on or 2 to 10 is a very different pattern than 7 to 7 consistently until they're grown and hopefully self-sustaining.
This is where I've seriously considered multi-family communal living, and wish it were more popular and mainstream.
Taking care of kids is relatively scalable, in that it's a full-time job for one person to "engage" (and I don't mean "watch" or "babysit" or "entertain" but more like "actively plan and execute a meaningful day's activies") one child, and it's nearly the same full-time job for one person to engage six children.
So I imagine sometimes how much better a job I could do if I could really focus and devote my full time and attention for 1 whole day out of 7 on a small group of children. What would we be able to plan and go out and accomplish and learn about? If you had 6 adults taking shifts with 6 - 10 kids?
And this is a deep confession that I've never really told anyone: I envy my divorced friends with kids. Every other week they (usually) are child free. And get to do things like mow grass, have a dinner with an SO at a place that doesn't have a built-in playground, or go on weekend trips on a whim. That guaranteed time without children that you get from custody agreements has a ton of perks. I won't admit this out loud, though.