So true. I heard a wonderful quote from John Bogle (famous investor) that 'Dieting is simple. But it's not easy.' He said it in the context of a discussion about investing. Follow some simple rules and stick to them; sounds simple but it's not easy!
With dieting, it's 'Eat less - eat fewer calories, and move more - exercise.' With investing, I don't know, 'Buy low, sell high'?