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.
An air fryer. It was a bit of an impulse buy and I didn’t think I would use it very much but as it turns out it’s much more versatile than I initially thought. I’m actually considering getting rid of my regular oven since I’ve rarely used it since I got my airfryer.