It would boil down to a very simple question. But first, you need to figure out what it would cost to maintain the lifestyle you want for the number of years remaining in your life, with an allowance for a margin that you may live longer than expected.
At a certain point, you could conceivably reach a net worth where that is attained plus a buffer, and from there on out, it's not about the money.
One would think that 20 mil at age 38 would put most at a level where they could afford a lifestyle they desire for the rest of their life, esp, with using the cash to generate income,
So, the simple question is, does what you do for work serve a higher purpose that you find justifies the time and energy it takes to do it. Again, with 20 mil in the bank, you're probably not doing it for the paycheck.
I'm sure we can all imagine certain jobs that would meet that test - that are compelling, rewarding, or benefiting others enough that you would basically do it when you didn't need the money anymore.