I knew when I took on my current job that I would be responsible for the tasks of many different specialties within the field. I feared that I would be responsible for everything, and those fears have come true.
It is true that for the most part all aspects of computing are inter related. Everything revolves around the Computing Device, you know - keyboard, mouse or other input device, a screen to display the info and some sort of processing power with the ability to store the info for later use. Or some combination of the above.