My dad barely qualifies as a millionaire in the loosest sense. He has told me that there is a certain threshold of wealth where you can just become reliably wealthier and wealthier without a big limit. It goes like this:
He has a friend from Berkeley who worked on Wall Street in the 80s and left with about $1000000 in his bank account by age 35
He used half of that money to start his own business which solar product that was greatly needed by other businesses in the area.
After about 4 years of that, he bought an apartment complex for some side income.
After 7 years the apartment complex has paid for itself, and he spends the profit that year on becoming a majority shareholder in another small business in the area.
After making money on that, he start another small business this time only loosely run by him with a separate CEO to run the company.
Using previously accumulated money he buys a golf course and now he is technically unemployed, but the dude makes between 3 and 4 million a year off of his passive income.
He called me a little while ago saying that his son is a bit of a s**t and that he wants to send him to the military school where I went. I wouldn't be surprised if his son never sees him.