Some people could win the lottery and still find something to be mad about. Being full is a skill, not an amount.

There is no quantity that produces satisfaction, which is inconvenient and worth knowing early. The feeling of having enough is generated by attention, not by inventory, and people who have not built it stay hungry at every level. That is why somebody with everything can still be genuinely aggrieved by a small inconvenience.

Practise the noticing part while your circumstances are whatever they currently are, since the skill does not arrive with the money. Once a day, register something you already have and would miss. It takes a few seconds. Wanting more is fine, and being unable to feel full never fixes itself.