How Do You Know When You're Unhappy?

What's the line between someone who is open to the next step that god has for them, and it is asking those questions throughout their life? What's the best thing i can do to glorify god in my with my skills and abilities and gifts? We know people like that as well, who never seem to be happy where they're at. How do you know when when you're falling into that trap verse s just being open to god's leading?