Focus - the most misused advice in business.
When we're in school, we're told to focus. If we're too slow, focus. If we're too smart, and bored, focus. Too interested in things? Focus. Not interested enough? Focus.
This is understandable from the perspective of the teacher. They have 30 rambunctious kids to control! How can they teach if they let the kids direct themselves!
Then, we start a business. Our bank managers, advisors, investors, they all tell us to focus.
This is also understandable from their perspective. They have a portfolio to run! How can they keep track of you, manage you, place you in the right category? How can they nail your communication strategy or approve your loan if you're always running after the shiniest thing you see!
Even without their biases, the problem is that the people giving this advice assume too much. They aren't aware of your options, just the one thing that's in front them. Often, this means their advice to you is to polish a turd.
"The amount of shit I have 97% done is embarrassing." -- Gary Vaynerchuck, 2008
Think about the consistently successful serial entrepreneurs that you know. They have their own portfolio. A portfolio of options, opportunities, and resources that's in constant flux. They have multiple projects on the go, and even more cooking slowly on the back burner. Only when they see the winner do they double-down and focus.
If you don't yet have a clear winner, think like an investor. Create a diverse portfolio, keep your options open, and invest yourself heavily when the winners start to emerge.