Lots of little things added up.

My physical self image is of a skinny distance runner, not a fat sedentary nerd.

I'm no longer married to a larger woman who encouraged me in habits that made me fat, because me being thinner was bad for her self image, and me being bigger helped.

I got outworked helping somebody move...by a size 0 girl. I'm a 6'4" man, btw.

Friend got diagnosed with diabetes for his 30th birthday...and I was 28 and probably less healthy.

Speaking of age, peers genuinely complaining they were getting old. Seriously y'all? Physiologically, we should be in the prime of our lives...I should get fit while I can still attain peak fitness. We aren't even halfway through our lives, hopefully not even a 3rd. We can't be old.

I noticed I felt tangibly better after eating healthier for a few days.

Following that, being homeless makes you really worry about your food habits. They've improved.

It's easier to eat healthier if you decide to adopt cooking as a hobby.

Moved. Then bus schedules changed. 50 min commute changed to two hours, on a quick day. For 4miles. 70+ minutes for 5 miles? That I could do all on residential streets by an extension to 5 miles? **** that ****, I'm getting a bike.

Wow, I'd forgotten how much I loved riding a bike.

MUP opened up that lets me do my entire commute on residential streets, downtown(lots of cyclists) or on a MUP/empty rural roads? Hell yes, let's cycle all 15 miles, both ways.

To give an encore to a common theme: watching people age badly scares the crap out of me.

Hearing people talk&brag about their running times, when I was minutes faster in the mile previously-much less the longer distances.

I developed carpal tunnel. Hard to have instruments and computer games as a hobby when your time with those things is so physically limited. Already figured out I like riding bikes, so let's make 'being active' a new hobby.

My mental health is SO much better with regular exercise. I'm not sure I could get through a workweek without it.

I like the social aspect of group rides/runs.

One of the things I love about playing instruments is the acquisition of skill, the tactile involvement in playing. Swimming is a surrogate for that.

It's fun noting objective improvements. More weight lifted, faster speed, distance comfortably traveled, etc.