The Superinvestors of Graham and Doddsville by Warren Buffett
I might be biased, I've been investing for 20 years and I did really well for myself. What I did can't be even compared to what the market did because we are talking about 20x versus 2x or 3x. However, people keep telling me it is impossible to beat the market.
Well, I firmly believe that in life you get what you focus on. It is that simple. So, I'll focus on what I do and the market can focus on whatever it wants to focus on.
I think that in 1984 Warren Buffett was bothered by the same question, so he wrote the famous article - The Superinvestors or Graham And Doddsville - to explain a bit what investing is. Enjoy the read and they you will see what is best for you. Here is my video discussion on it : The Superinvestors of Graham And Doddsvile Video