Feel very sorry for the future of the world, if kids have to be reminded you only live once. There are only 2 things you are GUARANTEED in life. Your birth and your death. Why remind yourself that you will in fact only live once. Stupid
I do understand you live only once but saying it non-stop for some sort of nonsense (for certain stupid people) I really don't like being reminded of it I prefer something like "Better live now or else you won't get the chance to later"