I was worried about the lack of returns for several years after I started investing. People told me that I should invest for the long term, but when I looked at my portfolio, it would go up a few percent and then go down again. I still remember what an investment advisor said to me: "Investing without a strategy is just gambling. You need a systematic approach to make money."

That's when I started studying systematic profit-maximization strategies instead of just "buying good stocks," because I realized that it's much more important to design the "system" itself, such as asset allocation, rebalancing, and tax optimization, than it is to pick individual stocks.

I think this is something that many retail investors miss: they invest based on returns alone, and often end up making less money than they think because of taxes and fees.