Twain isn't simply mocking fools—he's identified something uncomfortable that comfortable people prefer to ignore: self-doubt is often the real obstacle, not insufficient knowledge. A surgeon's paralysis over every possible complication kills more patients than a moderately skilled one who acts decisively. The wit works because it describes an actual trade-off we face: the person who knows enough to see all the dangers may never move at all, while the person who presses forward with partial understanding often reaches destinations the cautious never reach. It's a corrective to the modern cult of expertise, which whispers that you're not ready yet.