There are several incentives that motivate us to work on a problem: we want to improve our lives, we want to make a living, we want to improve other people’s lives, etc.
In general, I think the most satisfying incentive with the most driving force is the desire to improve other people’s lives. There’s just something distinctly rewarding about contributing to something that lifts other people up, or in some cases protects them, in meaningful ways.
Part of living an examined life is understanding what problems are worth your energy.
Focusing on problems bigger than you — where their solutions stand to support the needs of many and not just your own — is a good place to start.