I'm 45, well 46 in a month, and I've been programming since I was 17. I've worked in easily a couple dozen different languages from the lowly assembly code to the higher end object code. Sometimes I actually miss the control you had of the computer when everything was assembly, but on the other hand, the new languages really take a lot of the tedium out of the process and allow you to get to the important parts of your code. In any event, as I am moving on to iPhone development now and continue to learn new platforms, I certainly have not burned out and don't see myself doing so anytime soon. And I can say for a fact, all the mistakes I've made in the past have certainly made me a far better programmer even when working with a newer language. In the end, a computer is still a computer is still a computer and they basically do the same things now that they did then. Just far faster and with many more options. In my opinion the solution to not burning out,is to never let an employer use you as a commodity that they just use up and burn out. I've held my ground on never working constant overtime and making sure my employers know I have a life outside of work and I'm not their slave to be called in at their whim. And no, I've never been let go for holding my ground in this manner, while being flexible enough to come through for the company on a tight deadline. Just don't allow one tight deadline to follow another to follow another, etc, etc.