Optimism does mean a belief in the ability to improve yourself and the world. It’s a commitment to choosing and finding the beneficial element in any information or situation, and using it to make progress towards your goals. Belief is a precondition to action, and upward action requires a belief in the ability to move up.
We often feel overwhelmed by the amount of discipline that’s required to keep up with good habits. It makes us not want to start at all, or to completely abandon all progress when we lose ourselves to temptation, social pressure, laziness and unexpected disasters.