"After we had conducted thousands of experiments on a certain project without solving the problem, one of my associates, after we had conducted the crowning experiment and it had proved a failure, expressed discouragement and disgust over our having failed to find out anything. I cheerily assured him that we had learned something. For we had learned for a certainty that the thing couldn't be done that way, and that we would have to try some other way." -- Thomas Edison, the January 1921 issue of American Magazine
It's worth taking up initiatives that might not work, especially if the end result is something that would be worth reaching.
"Let's take a crack at this... it might not work, but let's see what happens..."
If you're trying to break new ground that hasn't been done before, you have to do so knowing that any given way you try to move forward is unlikely to work. You make a rough hypothesis and plan, you give it a shot, and you see if it pays the desired result at a reasonable cost.
It likely won't, but you usually learn something.
This applies, too, when you're chasing down more normal goals. Empirically, most people fail with their first attempts at a fitness regime, at improving sleep quality, at improving efficiency, at reading more, at socializing more, at earning more, at all sorts of things. The second, third, and fourth attempts also often fail as well.
But if you're dead-sure it's worth getting, you keep trying it different ways. You might take the same fundamental approach with a different mindset or slightly different implementation, or you might try something radically different. But you keep trying.
Most people need a sense of certainty that their plans will work, or they won't start. So they'll engage in complete certain but not-so-valuable activities. It lets them feel good, and feel smart, sort of. But embracing the other way -- "hey, this might not work (and likely won't) but I'll definitely learn something" -- is not only more fun, but it seems to lead to a much more enriching life.
Certainty isn't required to try things, and isn't possible for any given way to breaking new ground.
Take a crack at something meaningful. You're only going to succeed, even if it doesn't work.