IT is ever changing industry...If you have 15 years of experience and you don't upgrade your skills you're like an old car...which will take you from A to B but with some issues...unreliable etc...But if you're an IT professional who keeps upgrading your skills...then you're a fine tuned vehicle with turbo engine perhaps...may get well paid over the years for what you do...Unless you beat your competition year after year (fellow employees), you are a big liability to your company you work for.....and also a baloon about to explode (in your own mind)....coz you need that pay check for mortgage and all that stuff...you better try as hard as you can and stay at your work and hope for retirement someday with all the benefits that you believe you'll get.

I may be little off but this is somewhat IT industry seemed to me few years ago...now my dream is to go open a small grocery store near a fortune 500 company and sell rice and Daal to all the IT professionals who may buy from my small store.....in my case, I'd be selling the same thing again and again for years and year...and most likely at higher prices every few years.