Most of us come into design with a very cloudy understanding of typography. It's really not until your professor tells you "What font are you using? Never use it again", when you suddenly realize that you actually don't know anything.
One you start putting things into practice you start to get a feeling for the rules that seem to be general knowlege among more experienced designers. It takes a long time, but slowly you start getting the feeling for what is generally a "good font" versus the "bad fonts".
There is quite a bit of personality behind them. They can be stiff and structured and come of as very businesslike, or sometimes quirky and fun. There are dainty and delicate fonts as well as classic and refined ones. You start to understand the humor behind them a little bit and things start falling into place.
Being an addicted Pinterest participant, I'm constantly pinning things to my boards as inspiration I can one day hopefully use. I never realized how quirky the typography universe could be, as well as beautiful. I've had many a laugh looking at images that I would not have understood without coming to Tyler.