A big example of this in my life was doing my MBA (I was a hardcore developer/dev manager at the time.) While many classmates had specific goals like leaving a career behind or breaking into investment banking, my thought was more like "I got the time, my employer will pay tuition, maybe this will be challenging and fun."
Fast forward a few years, I "naturally" ended up in product management. Not because it was my goal, but because the time in b-school taught me how to think about strategy, markets, communicate more clearly, and just be more sociable and have skills to confidently meet high-level clients and not embarrass myself. In other words, "playing at business school" happened to give me skills that enhanced my life in an unexpected (though in retrospect predictable) ways.
Smaller examples of this abound. During COVID lockdown I randomly bought a raspberry PI and some basic electronic components. Soon after I ended up buying motor controllers, a tank chassis, sensors (and a soldering iron..) Without intending to, I went from someone who's "never done anything with electronics" to someone who "has built an autonomous rover that navigates by sonar." Completely useless but - for example - it opens up future opportunities to confidently work on a hardware business/product should an opportunity arise.
A final example - also during COVID lockdown - our living room in-wall AC was barely blowing air and also getting wet. Repair people said that everything is working fine, that's just how it is given the airflow in the location of the unit (which didn't make sense because my wife remembered it working better a few years ago.) I decided I was going to figure it out - for fun. I didn't know anything about ACs and I figured there's a good chance that I'll fuck things up more, but the "worst" would be buying a new AC (about $2000) which might work better anyway despite what the repairmen said. So basically I had "room to play"
Several days later, after several trips to a parts distributor in Queens, after learning about and switching out capacitors, etc. I didn't fix the problem. I started to try to measure the current going across the blower fan motor (I learned enough to associate the ice/condensation with insufficient air flow) when I short-circuited something and the motor sparked, smoked, and died. FUCK.
Here's the scene of devastation (at about 3am) when I finally extricated the old burnt motor out of the unit: https://ibb.co/crYxs4R
One more bike trip over the bridge to pick up a new motor, then one more because the new motor had a different thickness shaft and I needed bushings, I replaced the motor and noticed right away stronger airflow. Long story short, the old motor was slowly failing (before I made it fail quickly by blowing it up.) So now, we have a perfectly working AC and it cost about $300 (vs living with it or paying $2000 for a new one) and most importantly, I had fun and accidentally learned the skills that will make me a much more confident home owner in the future.
There was a funny exchange I had with a colleague when I took a day off to work on the AC. He couldn't believe I took time from "the big important job" to do mechanical work, but he was missing the point - the reason I had "the big important job" is that I do shit like this and acquire random skills that help me move forward.