Jack Hughes, over at the Tech Teapot, mentions a very appropriate subject for too many systems administrators: burnout.
As sysadmins, we're nearly always the go-to person for whatever happens. After a while, we start to get used to it, and lots of times, we can develop a hero complex, carrying the weight of the world on our shoulders, at least in our minds. This isn't healthy for a lot of reasons, the most important of which is your health.
Here's an example of what taking your job too seriously can do to you:
Not to ruin the ending, but the most disgusting part is that, while the guy was taking medical leave, his company fired him. To be completely honest, he's much better off without a company like that, and if your company would do the same thing, then so are you.
To quote Peter Gibbons, "We don't have a lot of time on this earth. We weren't meant to spend it this way. Human beings were not meant to sit in little cubicles staring at computer screens all day..."
Even one of the most preeminent Systems Administrators around, Tom Limoncelli advocates leaving the pressure at work when you head home. For those of us on call 24/7/365, that can be a little hard, but it's important to try.