Very handy in the kitchen draw for us old timers. I think need some sugar. Make a note of it and stick it on the notice board. There it stays until I have bought the sugar then I bin it and forget about needing some sugar. I buy quite a few things online. I use a post t note there and then for what, when and how much. I keep the post it note until the statement arrives. I then bin it having agreed that it was me that bought something.