Even many engineering problems are too difficult to know a priori that they will work. No new knowledge is needed as such, just the bounds on what is possible might be fuzzy.
If you care about solving your specific problem, you want to avoid having to acquire new knowledge. That's risky. (And I don't just mean knowledge that's new to you, that you get from reading a book. I mean knowledge that's new to humanity as far as you can tell.)
Eventually, someone will have to acquire some new knowledge to drive humanity forward. Just like in war, someone will have to go and fight the opponent; but you still prefer to achieve your objectives without having to fight whenever possible.
