Warren Buffett at Berkshire Hathaway’s 2018 Annual Shareholder Meeting on 05-May-2018:

What we do is not a complicated business. It’s got to be a disciplined business, but it does not require a super high IQ or anything of the sort. And there are a few fundamentals that are incredibly important. And you do have to understand accounting, and it helps to get out and talk to consumers and start thinking like a consumer in many ways and all of that, but it just doesn’t require advanced learning.