A self-made millionaire confesses the biggest financial mistake he's made

Youtube/Grant Cardone

Grant Cardone.

"Getting rich and becoming a millionaire is a taboo topic," he writes on Entrepreneur. "It shouldn't be taboo and it is possible."

That is, if you think big enough, the entrepreneur and best-selling author emphasizes: "The single biggest financial mistake I've made was not thinking big enough. I encourage you to go for more than a million. There is no shortage of money on this planet, only a shortage of people thinking big enough."

He's not the only self-made millionaire to encourage this level of thinking. After studying a number of wealthy people, self-made millionaire Steve Siebold found that rich people set their expectations high - they aren't afraid to think big.

After all, "no one would ever strike it rich and live their dreams without huge expectations," he writes in "How Rich People Think."

The bottom line: Aim for $10 million, not $1 million, the self-made millionaires encourage.

"To think that you can't get your share is ridiculous when you consider that there is approximately $41 trillion dollars in global circulation," Cardone writes. "There is a greater shortage of people going for 'more money' than there is money. Sounds like a simplification but my entire financial world changed when I realized there was no shortage except for the one in my mind."