I've talked to people who, one day, realized that their job wasn't what it had been. They hadn't changed, but the job had. Requirements changed, software knowledge needs changed, etc. Suddenly they were doing different things, or worse, were less and less qualified to do what they were doing anyway – and seniority wasn't cutting it.
Jobs change. They change in the skills needed, in the contacts needed, in the knowledge needed, and the vendors you deal with. Jobs evolve, grow, mutate – and even die off.
It's way, WAY too easy to assume that a job will be the same forever. We have names for jobs, good solid nouns and adjectives, that give us a sense of solidity, of permanence. Jobs are an activity and a process though, they slip out of the simplicity of nouns and adjectives (or end up adding new ones).
I can't emphasize this enough – stay aware of how your job – and your career – are evolving and changing. Follow trade mags, news, take classes, etc. Be aware of it, because chances are in this high-speed, erratic, global economy, what you do is going to change even if the title is the same – and what you do in the future will change as well. Make job review a regular part of your life – perhaps even meet with friends and fellow pros every six months to discuss your careers, compare notes, and seek advice.
With geeky jobs, it's even worse – stuff we progeeks do is often cool, cutting edge, creative, diverse, and evolving. The tools we use change, the goals change, the vendors change, what we produce changes. Manga moves in on comics, comics license to movies, movies create special effects unimaginable ten years ago, videogames becomes series of DLC, anime goes online, etc.
The way around this is, as I noted, constant research, awareness, and evaluation. Band together with your fellow progeeks, it'll make the bumpy – if exciting – ride much easier. The world is going to change – and so will your job, perhaps even the one you're doing right now.
– Steven Savage