This was my favorite part of college too. I think it was near the end of a really good networking class I took maybe my junior year when I distinctly remember chatting on AIM and thinking about how I could visualize approximately how my key presses were going from the hardware through the OS into memory into instructions on the CPU executing the application back out onto my screen and across the network to a server and on to my friend's machine for the reverse trip. It was a powerful moment. Of course as I've gone further through my career I've realized how far off my approximation was because everything is even more complex in the details, but I still think it was a fundamentally valid and valuable moment.

This is one reason I'm ambivalent about the skepticism around computer science / engineering programs as a prerequisite for a career in software development. It bums me out to think of people toiling at this work without experiencing that kind of bottom-up knowledge of computing. But I think this is largely a projection of my own personality on others; that would be a bummer for me, but I think many people don't care about any of that and just want to do valuable work for good pay.