Key Insights:
Investing is filled with regrets. There are missed opportunities where you pass on a great investment, selling prematurely just before a company you own goes on a massive run, not selling a losing investment soon enough and the cardinal sin of averaging down on losers.
Costco (COST) for me belongs in the missed opportunities bucket. When the stock was trading at $50 several years ago, I analyzed the company, wrote an article comparing both Costco and Safeway and then failed to buy Costco. A few months later, Buffett and Munger picked up Costco for Berkshire Hathaway (the price was around $80 if I remember correctly) and yet I failed to get over my anchor bias and buy the stock.
It certainly felt strange when I watched a video of Charlie Munger last year talk about how Costco was still an excellent company to own if you had a long enough time horizon of 30, 40 or 50 years. The stock was trading around $500 at that time.