I am not sure if this is a piece of wisdom or not, but it works for me.
It was derived from my father's saying long ago when I was a teenager.
He said: Son, if you make a dollar, you must save 95 cents and only use 5 cents.
i did not listen to him exactly, but I did save 50% of my income always.
Derived from this:
Never buy a boat unless you are retired. Let's sail others boat.