Having doubts will save you a lot of money.
Better to listen to your instincts than to heedlessly bulldoze forward.
That said, doubts can be dangerous. An army won’t follow a general that shows doubt.
Even if the general hides his doubts, he won’t be able to make decisions if he’s filled with doubt.
Sometimes doubt is just a wasted exercise. Sometimes you only have one course of action. If you have no options, ignore your doubts.
Keep moving or fail.