“Live each day as if it were your last.”
I doubt it’s a recent saying. I know Horace phrased it “carpe diem” in antiquity. I’m sure it predates the written word by aeons. It’s such insipid, useless advice, and it’s continued existence is a testament that mankind has never actually figured out much of anything better to say, at least not conclusively. It’s a fortune cookie missive that demonstrates that we as a species have no clue how to approach life, and we haven’t even narrowed anything down to the point where we can all go, “well, idk what the answer is, but it’s definitely not that.”