What’s one small thing you always forget to keep track of?

For me, it’s the everyday things that don’t feel urgent until they suddenly do: when I last changed the sheets, whether it’s time for a new toothbrush, or the jar at the back of the fridge that expired before we opened it.

I made Whenly to help remember those things without turning them into a daily to-do list. I’m curious what this looks like in other homes. What’s one thing you wish you could remember at the right time?