What It Really Means to Be Self-Disciplined

What does it really mean to be disciplined?
Discipline means self-repair, meaning you're always in a positive cycle.

Most people make money to spend it — buying a car or a luxury item, that's spending.
A few people make money to keep making money.
When you acquire a company, that's not spending; the money hasn't turned into consumer goods but into a tool for continuing to earn.

A higher net surplus than others is merely a starting point — if you can't put that extra surplus to work as capital, you'll end up no better off than simply working more overtime and consuming more.