I have been a lurker on this forum for quite sometime and everyone says, you are never to old. If you have that 'itch' that won't go away, I say go for it. I am 42, but 29. Just finished university, had a rough year with losing a job and some other personal situations. To say the least, I was miserable in that previous job that I held for 10 years. I always had in the back of my mind the thought of joining the CF. I cannot find a job that I am 'qualified' for on paper (meaning I have the experience), and unhappy and unchallenged in my current position.
I am currently in the midst of joining my reserves. I have seriously thought about going full time, but I want to get my feet wet first to see if this is a career path that I can enjoy for the next 20-25 years.
I am working on getting back on track with my fitness. I cannot do the basic push up requirement (female) and my running is non-existant (thank you knee surgery!). So I have a few things that I need to work on before I am comfortable to apply. It has been a few months and that itch is still there.
Go for it, take that challenge and embrace it.