Now why is this string tied around my finger?

When I don't want to forget something, I usually leave a note for myself, or I leave the thing I need to take with me or work on.  Yesterday morning, I woke up and found my flashlight on my placemat.  I remember setting it there to remind myself, but I couldn't remember what I needed the flashlight for, so I put it away.

Last night, when the lamp timer switched off, leaving me in the dark an hour before going to bed...  "Oh yeah, I remember why I needed the flashlight!"  In fact, I'd better change the timer right now, or else I'll forget it again!