The Great Discontent has a really interesting (and long) interview with Michael Bierut about his career in graphic design:
The reason I love graphic design is because it’s a way to get paid to learn new things. For example, let’s say someone asks if you’d like to design a book. It’s not about being interested in pagination, covers, binding, typography, or paper. Those are all important, but what really makes designing a book fun is being interested in whatever the book is about. Sometimes it’s a great and exciting book that you’re really into: that’s like someone asking, “Would you like to sit and eat ice cream with me?” But sometimes it’s a book whose subject you don’t know about at all, so you get to talk to people who may be the world’s foremost experts on that subject. Even better!
When I brief interns about a project, I don’t say, “It’s this big and it has x amount of words and pictures.” I say, “These people are trying to do this, they’re trying to get this message across, and their big challenge is that.” Those pieces of information put the project into a larger context. That’s how I learned when I was starting out. I was a pretty good designer in college, and I’m not sure I’m a better craftsperson as I was then. However, I’m a much better designer now because I made people pay me to go from dumb to smart over and over and over again.