I can understand where your millionaire friend was satisfied, Dave. First of all he didn’t put happiness dependent on material things. Expensive toys lose their charm quickly. It is like five days after Christmas and the child has become bored with his new scooter.
He was satisfied because he was in a position to constantly gain greater understanding of life and the universe through books. So mentally he is always evolving upward, without having to rip himself apart in the process.
The last 23 years of my life has been a mini version of that sort of satisfaction through reading and writing, so personally I see few negatives to satisfaction of such a kind.