Good companies can still be bad investments.

This sounds obvious, but it is easy to forget. A business can have strong margins, high return on capital, loyal customers, and still produce poor returns for shareholders if the entry price is too high. What matters is not just quality, but the relationship between quality and price. When expectations are already extreme, even strong performance can disappoint investors. The company grows, executes well, and the stock still underperforms because the valuation was stretched. I learned this the hard way. I used to focus almost entirely on business strength. If the company was excellent, I convinced myself that price would not matter long term. In some cases that worked. In others, it led to years of stagnation. Now I separate two questions clearly. Is this a strong business? Is this a rational price? Both must be true. How do you personally balance business quality against valuation discipline?