I bought a piece of 1.5 inch stiff foam to try to fix a sag in a bed. It didn’t work but having that thick piece of solid foam around has been a life saver.
Need something flat to put a laptop on? Throw it on the foam. Going to be doing something that requires you to be on your knees for a while? Get the foam!
It went from stupid purchase to something I’d gladly replace if it broke.
A bicycle. It was kind of a stupid purchase for me because when I got it I wasn’t really into doing exercise or outdoor stuff. 900 dollar on clearance gravel bike back in March 2019. I wound up living on that thing, worked my way up to a 160 mile solo gravel ride by September 2019, biked to work in 2020, got into running in 2021, ran a 50K in 2022, now I run to and from work. I put 10,000 miles on that bike in 2 years, explored my city/greater metro area until I ran out of things to explore, pretty awesome impulse purchase