> You only need a 20ish pound set of weights to build muscle, oddly. Don't even have to spend a ton of time on it. Can do a basic set of curls/whatever while cooking breakfast.

Eh, you can do almost anything with anything at a sufficient intensity frequently enough that you'll build muscle, and you definitely should, but I just feel like the more important thing is to find a good feedback cycle. Everyone is a little different, some people end up liking calisthenics or climbing or hiking or a combination of them, some people like the gym or free weights at home, but you gotta engage with it enough to have a serious possibility of either feeling results or other rewards, or lack thereof enough to move onto another idea.

If you don't see or feel results at the gym in the first month, if you set yourself up right you might meet someone to chat with and that may help spur you to keep going regardless.

If you don't feel results hiking after your first time, you've at least had an outdoor adventure. You may still have no motivation, try the other idea, go swimming whatever, but there are at least some other qualities present that help reinforce the desire to do the activity.

Eventually, you might find that your new default mode of operation in every other facet of life becomes activity first rather than something to fit in just during breakfast. At that point, it's harder to not work out or get activity than the reverse. 3 days go by and it feels odd that you've not done anything demanding in a while, and although it takes effort, it becomes easy enough to maintain long term after a certain threshold.

I'm using "you" in the general sense here, and otherwise agree with you, I just think the easiest and most private activities tend to reduce your surface area for discovering other ancillary benefits.