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.
Rechargeable AA and AAA batteries. I really didn’t think much of it at the time but I have been very happy to have them at hand especially once I made a system to keep track of the ones that needed recharging and the ones that were fully charged.
as long as the capacity is good… i accidentally bought 500 mAh batteries recently and they’re completely useless… I can use them just for the clock… luckily i have 2000 mAh ones, which I use a lot.