My thought is that Satoshi probably has several identities - I myself use multiple identities and have done so for over 20 years. So he can still show off using one of his other identities any time he wants. Sure we think his main identity has 500,000 bitcoin. But, perhaps he has a dozen more identities. Maybe he poses as someone who has 100 bitcoin or 10 bitcoin. He could live off of bitcoin and no touch his main stash for 30 or 40 years. Would he ever reveal himself? Probably under the right circumstances. But, I have no idea what that would be. He is also probably 10 times smarter than me so who knows what can motivate him. I am just glad that he does exist.