Average is NOT Normal

I found an interesting slide on slideshare. We all normally rely on averages and means to work out whether something is worth the effort or not. But averages are not actually normal phenomenon.

Consider the stock market as an example. For the last 80 years, it has averaged 10% increase. But if you invest your money on that basis, you may not grow by 10%. Why? Check this slideshow out:

It all depends on where you start, where you want to go, and your behaviour / skill.