How Warren Buffet learnt the lessons in investing.

I came across an article where Warren Buffet tries to explain how he learnt the lessons in investing.

I bought first stock at age 11. I bought 3 shares of Cities Service Preferred at $38 ¼ . My sister followed me and did the same. The price then declined to $27 and sister complained every day on the way to school. When the stock recovered to $40, she and I sold. I had a $5 profit. The stock then rose to $200. The lesson I learned was not to get involved with others on investments, or else their emotions will spill over.