Live each day as if it were your last is terrible advice. I’m not sure how I would behave if I only had one day left but I doubt it would be sustainable. I don’t suppose it is meant to be taken literally. It’s intended to encourage you to value what time you have, to treasure every moment, but life is full of shit like visits to the DMV, dentist appointments, and waiting for that little blue bar on your screen to finish loading. There is plenty about modern life that is best left unsavored.
