I'm 56 and have been a techie since my first programming job in 1974 (a Univac "mainframe" with 32k BYTES of main memory, using RPG II), to today (designing REST APIs, programming in Java, Ruby, and Python (plus I need to pick up a couple more scripting languages in the next year). I've loved it all along.
For me, I've never been interested in the management track. Fortunately, I am currently working for a company (Sun) that believes in the value of individual contributors, and has parallel career tracks for technical and management folks -- well at least until the Oracle purchase goes through, then we'll see what happens :-). However, I have started from the assumption (from the very beginning) that anything I thought I knew about technology would be non-useful (from a career enhancing perspective) in 3-5 years, and laughed at in 5-7 years. So, I've committed myself to a lifelong self education regime to make sure I'm always current on the latest and greatest technologies. It can indeed be tough keeping up with the young bucks from an energy perspective, but there's a lot of value that comes from experience and being smart, so you can be more productive without having to work quite so hard :-).
For you, I will agree with what others have said, and suggest you go with your passion. BUT, I would suggest you *not* assume that a choice today has to be a now-and-forever type commitment. (Save that kind of commitment for marriage -- coming up on 35 years myself :-). I know lots of folks who have switched back and forth over the years of their careers, and enjoyed the fruits of both tracks. As long as you stay current with trends on both sides of the fence, you'll always have that option -- plus, techies that know something about management, and managers who know enough tech to not get snowballed, are going to be better at their job of the moment, and thus more likely to get rewarded.