This is why I'm leaving the field for healthcare at the age of 39. I saw the writing on the wall when I worked in SV for over 10 years. I saw how young most of the employees were at most of the start ups and smaller companies. I saw that the older folks worked at tired corporate cogs such as IBM--nothing wrong with that, just not for me. I also saw that these older folks were just not capable of keeping up with the rapidly changing field. In fact, I worked with one guy in his late 50's or early 60's who had a Ph.D. from CalTech in EE, and he either would keep forgetting, or not understanding, what Telnetting or SSH'ing into another machine was about. I remember working with the guy and setting up a distributed monitoring system, and we were SSH'ed into several different machines on his laptop. The way he kept stumbling through the installation and configuration of each machine was pretty disheartening to see. That wasn't the only older person I've worked with who had trouble keeping up. It was ALL of them. Mind you this was at IBM, so I don't know if it was the corporate culture that eventually did these guys in or their age. I will never know. What I did eventually realize is that I needed to find a different career. So, here I am, 39 and starting a graduate program in health care.