Its challenges are formidable, so only certain investors should consider it.As the great investor Peter Lynch once suggested, investing in companies that you know well and interact with every day can be a great way to exercise an edge and make a profit. But that doesn't mean you should invest in every company you know well.On that note, Walgreens Boots Alliance (WBA 4.19%) is a business that many of us are customers of, and often for many years. Yet it probably isn't the best choice for investors who prefer ...