I think the best thing to do is imagine what you would love to do if education, money and other things were not in the way.
For me I'd love to get a commercial pilots license and do that for a career, have been saving for a while now so I might just go and do the training some day. I've even considered selling the Z to be able to do that as a career, but I love my Z too much.
I guess my point is, go for the job that you would love to do and don't let others tell you its too late or its unreasonable if you really want something you will find a way to get there.
I hated IT for a while back there, then I landed a job at Google and I must say I really enjoy working at Google right now and I really enjoy what I do. I could find higher paying jobs, but as Aegean said I wake up in the morning and look forward to coming in and seeing my work colleagues (I can actually call them friends).
I still get a case of the Monday's at times, but its not the "fear" I used to get on a Sunday night.