One cloudy day in 1990, I am listening to a lecture in on my Finance classes in undergrad. The professor makes the point that there is no way to consistently beat the market, because if there was one, everyone would copy it or the one who knows how to do it would keep it secret. That makes sense to me.
Later on, during that class, he mentions Berkshire Hathaway (BRKA) and how Warren Buffet has been able to beat the market. Because what he previously said made sense, I conclude that Warren has been just lucky and do not invest on BRKA. The stock was trading back then for $6,000. It now trades for 250,000. The ROI has been close to 20% per year every year.
My worst investment was not to buy BRKA in 1990.
Luckily for me, one sunny Saturday 20 years later, I am reading the Wall Street Journal and read again about BRKA. What I read sounds interesting so I go to my PC and download their annual report. I realize the first few pages are an excel table (unlike all other annual reports which are filled with pictures).
I placed an order to buy that evening. I have been a happy shareholder ever since (the ROI in 2016 was over 20%)