Coincidentally, I'm also in chapter 14 of the same book right now. I love computers as well, but I specifically decided to study C so that I could create my first computer game, which will be a "simple" text adventure. I have other aspirations down the road for my new hobby, but for right now, I'm keeping focused on my first goal of a playable game that doesn't entirely suck. When I say simple, I realize it won't be simple for me to code at all, since I'm completely new to this stuff.
You mentioned incorporating a GUI for your program... I must admit, I was originally going to only utilize a console-based, ASCII-graphics format for my game, but since I happen to be using an OLD copy of MS Dev Studio, I've recently decided that I will create a Windows version instead, with simple interface that gives me more control over the appearance of my text, such as TT fonts, etc.
So, my best response to your quandary would be: what about creating your own computer game?
Best of luck to you in your programming, and have fun!