Wealth = Have ÷ Need

Good mental model, but I feel its intended audience is people who have their basic needs met. You need at least X calories a day (ideally, healthy ones), you need a roof over your head, etc.

Keeping that context in mind, recognizing that many of our "needs" are actually "wants" (or at least on a spectrum), and that they are more under our control than income, is a superpower. Especially as your income grows, you adapt to the hedonic treadill and/or are under pressure to keep up with the Joneses.

Or as I remember it:

Rich is not he who has a lot, but he who needs little.

i think this make sense once you've climbed up a certain amount on the maslow heirarchy of needs. then you can start to make choices about luxuries and must-haves.

for me, it's internet access, a warm bed, 3 nice meals, hot running water and peace and quiet (not living with noisy neighbours).

those are my needs. assuming good health.

No it isn’t. That’s not true.