One thing I have learnt from all these great men is that one can be very lucky or talented at making money, but unfortunately don't have that money management skill. Alot of people don't know that being able to manage the money you earn and multiplying it to produce more money is a skill on its own. It's too bad that this great men only lived for the present and never made good plans for the future.
Maybe some did make plans for the future by borrowing to fund their investments, then the unfortunate tragedy struck them. Being rich means having high income/purchasing power, it does not mean financial security/freedom. Proper planning and financial discipline can bring about generational wealth.