Formal vs Informal Learning

I am currently a college student, and have been for six years now. No, I'm not going to be a doctor or lawyer either. I'm actually going into Construction Engineering. I'm only part time, so that is why it's taking so long. Regardless, that's not really the point of this post. The point, however, is the contrast between formal and informal learning. Also, what is the difference between a hobby and your life goals?

For starters, by formal learning I mean time spent in the classroom or comparable atmosphere. By informal I mean what you learn in your own time on your own means. It's ironic that no matter the subject, it always seems that formal learning is always far worse than informal. By this I mean you can learn about the exact same subject matter in both styles, but you are likely to comprehend more the informal way.

Take me for example. I am studying Construction Engineering. More specifically I am taking a structural design course this semester. Now, in the classroom it's very frustrating. I sit there and frantically write notes so I don't miss anything. The organization is great, but sometimes Greek symbols and random equations get really confusing. Furthermore, I find myself constantly worried about the next quiz or test. Now if I was to study structural design on my own I don't see it as really "learning". Say I catch a program on TLC or Discovery. The topic interests me so I watch vigorously, but am really not aware that I am actually learning. As I sit there I make comments like "That's cool." or "That makes a lot of sense." I don't tend to make comments like that in class.
My point here is that it seems that formal learning, although more in depth and worth more credit can seem more like work than interesting.

Now on to the second portion, hobby compared to life goals. In other words, how often is a person’s hobby interests the same or related to their direction in life, or their career goals. Again, taking me as an example. I am studying Construction Engineering, with a career goal to be a project manager or similar. One of my major hobbies, the reason I'm on GEEKS, in computers and tech stuff. The two really don't coincide with each other. They can in certain aspects, but as a whole they really don't. I love researching new ways to integrate gadgets and what not. I also tinker in my free time. Then I go to class and learn things about building structures, soil properties, and concrete breaking strength. That's not really the tip of the iceberg either, but whatever. My point here is that it's interesting that in many cases people have their career goals planned out, but are also very passionate in another field. Which leads to the question of is it really possible to make a career out of your hobby, and at what point does it stop being a hobby.

I'd like to here your thoughts, so please comment! Thanks for reading and I hope you enjoyed.