You are not that special (and neither am I)
You are not that important. Don't feel too bad though. I'm not that important, either. What am I talking about? I'm talking about an individual's value within a company of any significant size.
Let's say you have a job somewhere and you're really good at what you do. Maybe you are the number one performer at whatever it is, and everyone knows it. Maybe you take more calls than most people, or make customers the happiest, or write the best code, or come up with all sorts of brilliant ways to make things more efficient.
It doesn't matter. I'm just going to say again that odds are pretty good that you aren't that important to that company, no matter what you think. I realize that's quite a claim, and now I have to back it up. Here's my basis.
Let's say some idiot coworker has started doing bad things to your desk while you're not there. Maybe you had a remote controlled car sitting there one day, and the next day it was smashed. Next to it, there was a note from him claiming "it was an accident". Some weeks later, other things you had done to personalize your cube had been taken down, or otherwise vandalized. This occurred numerous times, and all of it was unambiguously attributable to this person.
You'd probably think "well, the company should take care of me and will get rid of this guy, since I'm the very top of the heap, and they need me". Again, you'd be wrong. Unless you are the only person who does what you do and that task holds everything else together, you just aren't that important. Sorry.
I can see why this kind of thinking exists. It basically goes like this: you bring a significant amount of "awesome" to the table. Therefore, if you should leave, the company would no longer be as "awesome". This may actually be true! Still, it doesn't change my position on this.
The error is thinking that a company needs to be awesome to survive. In reality, it can go on being blah for a very long time with no fear of going out of business. It would take a concerted effort to actively bring it down, like an embezzlement scam or hostile takeovers. A down-rating of internal abilities is just not going to do the job in any timeframe that you or your boss would possibly care about.
So, if your entire basis for trying to get things done is that "you are somebody", you might want to reconsider that. Chances are, you aren't.
I'd love to see a counterexample, like if someone special had the "hearts and minds" of a bunch of employees, and when that person quit, a non-trivial number of other employees followed suit. That might be enough of a shock to bring about the end game for a company. Anything less probably wouldn't cut it.
I suppose those rare cases where someone is the "pet" of a much higher-level person within a company might also apply, but how often does that occur? Once you get a company much past the size where you can track everyone else in your head alone, forget it. The odds are not in your favor.
Unlike some of my other posts, this one does not end with a way to avoid the problem or keep it from happening in the first place. I just don't have the answer. It may not even be a solvable problem. Thoughts? Hit the contact link and let me know.