The fishing analogy from the bitcoin standard by nostr:npub1gdu7w6l6w65qhrdeaf6eyywepwe7v7ezqtugsrxy7hl7ypjsvxksd76nak is what comes to my mind.

In a situation where you are catching fish by hand to feed your family:

If you sacrifice some of your time from fishing in order to build a fishing pole, you will be more efficient at catching fish and that will allow for more time. That time can now be spent building a boat.