Let’s say you rescued someone, somehow, from imminent, mortal danger. You saved their life. Saved it for what? A later date, when something else will take it.
One thing to learn early on is that oneself and everyone ever is going to die. It tends to restrain egotism, give a useful persprective of others, plus I just abhor the phrase “X saved Y’s life.”
I’ve always finished the phrase in my mind: “…for later.”