6 timeless lessons about wealth from a nearly 20-year-old personal finance classic

Robert Kiyosaki grew up with two father figures: "poor dad" - his real father who died with bills to pay - and "rich dad," who started with little before becoming one of the richest men in Hawaii.

Both fathers were successful in their careers, worked hard their entire lives, and earned substantial incomes, but one always struggled financially.

Kiyosaki started to notice fundamental differences in the way "rich dad" and "poor dad" thought, spoke, and acted: "I noticed that my poor dad was poor, not because of the amount of money he earned, which was significant, but because of his thoughts and actions," he writes in the personal finance classic, "Rich Dad Poor Dad."

Here are six timeless lessons he learned from "rich dad" that helped Kiyosaki master his money, build wealth, and ultimately retire comfortably at the age of 47: