I'm sorry, but i can't see how he spent $300 million so quickly. Even if you buy a mansion and buy cars and jewelery, it should still be enough for you and your damn grandchildren.
Richard Pryor blew away 30 Million in Brewster's Millions in one month so I am sure Mike could blow $300 million over his career. Mike Tyson doesn't strike me as a who is man good with his money.