Everyone says you shouldn't run a supermarket (i.e., hold a diversified portfolio), but I can actually make money by doing just that. Everyone needs to find an investment style that suits them. I can't hold on to a single stock if the position is too heavy. Even though running a supermarket means holding many stocks, I can hold them all. Taking a small bite from each can still be filling, and I don't feel the pain even during a big crash.