Earlier quoted context omitted.
But one important part of their success was to invest their income. I know too many people that use their money to consume. Investing early in your life is what makes the difference. It's very easy to spend it on little things and claim to not have anything to invest.
> I know too many people that use their money to consume. All those dumb poor people wasting their money on food.
Consuming means using resources on things that immediately loose their value. If you for example buy a house, that's not consuming since the house has inherent value.
But if you yourself the newest gaming rig, the gaming rig is consuming the money. This is what Americans mean when they talk about consumer society.