Peter Lynch doesn’t advise you to buy stock in your favorite store just because you like shopping in the store, nor should you buy stock in a manufacturer because it makes your favorite product or a restaurant because you like the food. Liking a store, a product, or a restaurant is a good reason to get interested in a company and put it on your research list, but it’s not enough of a reason to own the stock! Never invest in any company before you’ve done the homework on the company’s earnings prospects, financial condition, competitive position, plans for expansion, and so forth.