Maybe just me, but two things -

1. You don't care about X until you do. Like, you can go for years without worrying cholesterol. And then you can have a reason to care about it and all of a sudden you do. The reason can come from something that forces your hand or just because you take an interest in a subject.

2. Altruism. Think less about care and more just doing without expecting anything back. People notice, especially with selfless conversation.