You can think of it as "how much benefit I get from a thing".
What he is referring to is diminishing marginal utility, which is that as you consume more and more of a good (in this case, income) you derive less benefit from it. https://en.wikipedia.org/wiki/Marginal_utility
This is backed up by psychology research indicating that people hit a happiness plateau at some income level.
You can think of it as "how much benefit I get from a thing".
What he is referring to is diminishing marginal utility, which is that as you consume more and more of a good (in this case, income) you derive less benefit from it. https://en.wikipedia.org/wiki/Marginal_utility
This is backed up by psychology research indicating that people hit a happiness plateau at some income level.