Of course I worry about it. But when I'm sitting on the plane, I try my best not to think of it.
I also try to book seats towards the end of the aircraft because statistically this is the safer place. I know, I know, this doesn't help too much if a crash does happen, but at least I've done my part.
I also have trust in others. Thank God that (again statistically) Canada's pilots and maintenance crews are among the best in the world.
So just fly when I have to fly, and then try to keep myself busy on the plane by eating, drinking, reading, sleeping...