An idea is a tough thing to grab hold of. On the one hand ideas have provided the catalyst for anything valuable ever created. On the other, an idea is worthless until it is effectively communicated and executed.
That's why the ability to focus on an idea is so important to an entrepreneur, an artist, or politician. If you can't spread an idea, and put the brush to the canvas, the idea dies on the vine.
However, there are two kinds of focus: The good kind, and the bad kind.
When you have an idea, you must be able to describe it in one sentence. There's no other way to get your idea off the ground. You can worry about the big grand vision, the one that's so hard to explain, after you get that one sentence off the ground.
If you're starting an art movement, describe the movement in one sentence and keep creating artwork that fulfills the expectations of that sentence.
If you're starting a company, create a sentence first. Then build the simplest product that fulfills the expectations of that sentence.
If you're organizing a fundraiser, attract donors with 1 sentence, then fill in the details at the bottom of your website and posters.
Ideas that can't be told in one sentence don't spread because people can't focus on them. They are blurry ideas.
Think about every good idea that you've heard and then passed along. You probably introduced a friend to the idea using a single sentence. Then, when you had the attention of your listener, you started filling in the details as they (hopefully) asked a few questions. If you begin your story by pushing too much at your listener, saying the same thing more than once, stumbling over details, everything gets blurry and they lose focus. The idea dies at that moment, because it can't be spread.
Good focus brings an idea out, away from the background noise.
Bad focus is when we refuse to change our idea. Somehow we become so attached to our idea that we think if we focus on it and keep telling it the same way then other people will eventually "get it". This fallacy reminds me of the definition of insanity: doing the same thing repeatedly and expecting different results.
Ideas are malleable. In fact they have to be, because they are usually terrible when they are first born.
Ideas need to mature, and to do that, they need to be exposed to a real audience, revised, and exposed again. Keep doing this until the idea spreads. You won't get it right on the first or second try.
Bad focus is when you believe you can spread your idea by simply "trying harder", when the reality is more likely that you need to mature your idea.