Hi Ska
I began teaching when I was 22, now I'm 50. It has provided me with an intersting, solid and relatively well-paid core job over the years, but I have dipped in and out both to have kids and to work in other jobs. If you can hack it it is an excellent job with skills that do you good in all walks of life, and with qualifiactions that don't outdate and are valid abroad.
You need energy, common sense and adaptabilty, plus a little good fortune in ending up in the place that's right for you. Lot's of people moan as in all jobs, and the media loves school-related horror stories, but the show goes on and everyone will always need teachers.