In today’s IT world you have to choose: Either you are going to specialize in one area of IT and be on a constant hunt for mastery of that technology, or you remain an active IT generalist constantly learning the basics of many new technologies. You cannot be someone who learns only a handful of technologies and then expect to have a career in IT. Even if your organization is not requiring that you learn new skills you must require that of yourself.
The reason for this is that the technology that you know and are comfortable with is going to be replaced. It is inevitable. The first SAN I ever worked with was a whopping 2TB in capacity and it took up about 12 U of rack space. Now I can buy a single hard drive with more than 2TB in capacity for next to nothing. I used to setup 10Mb networks for simple TCP/IP needs, and now I design 10Gb converged infrastructures that are going to be eclipsed by 40Gb technologies just over the horizon. I used to install DOS on PCs and then laid Windows on top of that operating system, now I virtualize entire datacenters on clustered hypervisors.
I have gone into some organizations and have heard the IT staff say “I do not want to make things anymore complicated. I just want to meet this one need, but leave the rest of the infrastructure alone.”
I sympathize, but this is just not possible. The technology is not designed with your comfort in mind. The technology is designed to enable the future. The technology is designed to make what was once impossible commonplace. You have no say in the matter. The market, the needs, the innovations, and the constant search for a better solution have no pity for you. Those waves are going to keep on coming.
Diving deep might lead you to unknown treasures. Swimming with the current might lead you to new lands. Treading water will only result in you drowning.