Getting a job as a high school teacher

[Education&Law]

I really want to teach high school, but everyone keeps telling me it's such a bad idea because I will never find a job. When I attend teachers college here in Canada (will be attending university of Ottawa), I'm pretty confident that i'll be able to finish near the top, if not at the top, of my class. I had nearly all A+'s in undergraduate. Even if I finish with excellent marks in teachers college, will I still have no chance finding a job anywhere in Canada? I'm so confused, it's like everyone just keeps saying there are literally 0 jobs, but I had plenty of young teachers a few years ago while I was in high school (who were full timers) who clearly weren't super brilliant people or anything like that, so how did they get a job? 

 

If someone could weigh in on this it would be greatly appreciated, I'm really confused about my life right now..