The most important thing in terms of your circle of competence is not how large the area of it is, but how well you've defined the perimeter.
Warren BuffettIf you own a wonderful business...the best thing to do is keep it. All you're going to do is trade your wonderful business for a whole bunch of cash, which isn't as good as the business, and you got the problem of investing in other businesses, and you probably paid a tax in between. So my advice to anybody who owns a wonderful business is keep it.
Warren Buffett