I'm going to try to be brief here.
When you sign on, you're probably in your late teens or early twenties, and you're not even thinking about it. When you get to the point of contemplating retirement, even if you're 10 or 15 years away from it, you are trapped because of the terms of the pension. It's probably based on your best five years, and you can't afford to go anywhere else. You are what we call a prisoner of pension. You have to stay there because it's too lucrative not to, and you're definitely staying with the idea that you're going to get what you were told.