Identifying what you truly care about is a ever winding path, not a straight line. It requires a lot of self-reflection. It requires insight into your own history, temperament and dreams. Passion for a cause or need arises from both failures and successes in life, from joys and tragedies. Some passions focus on the needs of one person, some on the needs of a large group. So what tweaks your emotions . . . it should be personal, not what others say you should care about. Passions for a cause should not mean you want your picture in the paper or your work to look great on a resume.
Passions change. They morph and evolve. The most important thing is to care . . . and then figure out what you can do to make a difference.