Here’s a list of people who made it big before the age of 25: http://money.msn.com/investing/how-to-be-a-millionaire-by-age-25-kiplinger.aspx
When on the road to becoming a millionaire, for starters you must understand the significance and the true value of money by unfolding queries like: Why do we need money? How did the use of money come about? How does one accumulate money in the first place?
Before the invention of money, we humans indulged in what was known as the barter system, in which we traded things with each other for clothes, foods, and even other items as per the agreed exchange-rate. For example if you wanted apples and you only had oranges, you could trade your oranges with someone who had apples. Now the problem arose when the person who had oranges didn’t want any apples, therefore the exchange came at a halt and could not be carried out.