Then next week, as you are saving your nth child, you notice that this is the first child you saved. That child fell into the pond again!
Years later you meet a child you saved. That child is now a grown adult. They kept living near the pond in a dire condition. As a consequence their whole life has been miserable, and they made people miserable around them.
That child is now an adult. They had 10 children. 5 of them fell in ponds and drowned.
I’m not saying that that’s what happens in real life. Just that the analogy never considers those cases (same disclaimer as OP).