If you carry around a water bottle, but sometimes, forget how many times you've fill the bottle up, put some rubber bands around the bottle and remove one every time you fill up.
So, if you need to drink 8 bottles, put 8 rubberbands around your bottle and your day isn't done until they are all gone
So, if you need to drink 8 bottles, put 8 rubberbands around your bottle and your day isn't done until they are all gone