*Please note: this applies only to me. You should not expect to feel exactly the same way. If you do, that's cool, I guess.*
Graphic design is almost all about the humanity--your projects have to connect with your audience and you evoke certain emotions. That is extremely fascinating. Of course, there is more than that that makes graphic design so interesting. Color theory is one of the coolest things out there. Who knew colors made you hungry? You must pick and choose your color template according to what you want others to feel. Psychology ties in tremendously to graphic design, and dictates how people perceive your work. That is something to be amazed by.
Graphic design is fascinating, interesting, amazing, and colorful.