Are there any household gadgets you found unexpectedly useful after you'd gotten them?
I was thinking about how I missed having an indoor thermometer that measures humidity. It's such a small specific thing, one I'd never think of getting unless pushed to it (which I was by one particularly dry winter). But I like having one now.
What are your small, "random" or "junk drawer" type of gadgets that you actually use or like having around?
The idea of getting something before I know its usefulness confuses me. Do you mean finding that something is more useful than you expected?
If that's the case, I once had an alarm clock which curiously had a thermometer in it to measure the temperature in the room. I was able to use it - for years - to hold my landlord to account for being shitty on the heat during the winter.
I have a digital clock with thermometer feature and a dedicated thermometer. I've been logging the measurements every half an hour for months. The clock is ~1.5-3 degrees off (or the other way around, who knows). Just be aware they are not always super accurate.