imo systems programming is more old fart friendly and arguably more interesting than most "fancy" new tech jobs out there. I'm 35 myself and so far age was never an issue during an interview.

due to high demand in Europe where I'm at, I don't expect we will be forced to change careers in foreseeable future, however sometimes I think driving a garbage truck may be more desirable to pop-ing yet another problem from the never ending task queue.

age in itself is not a problem. the real problem is losing enthusiasm and drive to perform for others. that may or may not come with age and realization you are a hamster in a wheel as opposed to building something of long lasting value you can reap benefit of in old age.