(IMHO) Unless you're one of the actual IT/IS people in a large organization, the image that come to mind is a scene from "Apocalypse Now" What's-his-face is in a hotel room in Siagon, telling the listening audiance "Every day I spend in this room I get weaker, every day Charlie spends squatting in the jungle, he get's stronger" (I probably blew the quote, but that's the jist of it). Every day spent staring at a single network (or not working directly on a network), you start to get behind. If you don't take it upon yourself to pick up some books, or get some equipment of your own (PCs, LINUX, Solaris, hubs, switches, etc) and play with it, you get so far behind it's almost imposssible to catch up. That's one of the reasons I like coming to Anandtech....exposure to networking setups and scenarios I'm not likely to see on the job, or at home (I have some semi-serious stuff in the home network).
Even in a day-to-day support role (customer support), you don't really live with a network...you help folks put out fires, look up code compatibility and interoperability issues...stuff like that. To some degree, even if you ARE one of the network folks in IT/IS, you only live with a specific subset of the available universe of networking equipment. Most of the problems you see are recurrent and specific to the layout of your network.
If you're lucky/unlucky enough to be working on huge networks, you get to see a lot of stuff. If you're in a small-to-midsize place, chances are you're not going to be hands-on with the hardware that much....a great place to start, because you kind of work into the roles assigned to you....but the challenge kinda wears off after a while.
If you want to learn a broad spectrum of equipment (even within a specific subset, like Cisco, who has equipment in just about every arena), probably the best job is a small consulting / rent-a-body place, where you work on a couple different networks on a regular basis. The variety of equipment and configurations forces you to think and learn...makes you more flexible...gets you out of the "If the only tool you have is a hammer, all the problems start to look like nails" mode.
The tough part for the newbies is looking beyond the performance and "IWBC" factors (It Would Be Cool), and look at things like ongoing maintenance, vendor support, reliability, monitoring capability, scaling and growth potential....and a proverbial sh!tload of other "interesting" parameters. For those of you in pursuit of better/gainful employment...you may want to mention these kind of issues to the person doing the interview.......
And, for the Mucman, it doesn't hurt to be a jack-of-all-trades. Generalists are a valuable commodity. Best case, learn about the entire system, then go a little deeper on the sub-systems that you find the most interesting. In the US Submarine Service, every guy on the boat has to learn how to do everything, even though they are highly specialized in one (or two) areas... versatility can save the ship.
Anyway...that's my take on it...um, what was the question again? (Damn drugs........)
FWIW
Scott