Helen Keller's claim cuts deeper than mere cheerfulness—she's identifying optimism as a *prerequisite*, not a reward. Notice she doesn't say optimism helps achievement or makes it easier; she says it *leads to* it, as if the confidence itself is what sets the machinery in motion. When a student sits down to study for a difficult exam while genuinely believing they can improve, that belief actually changes how their brain processes information—they persist through confusion rather than shutting down. Keller knew this from her own life: learning language without sight or hearing required her to maintain conviction that communication was possible before she could prove it was.