That's because you're a woman, AK. Of course you can take pain.
Also root canals, so what? Both my father and I got root canals and he was the only one to complain about his mouth hurting.
To treat a root canal you have to drill directly into the tooth nerve. Only crazy people or people like me, who have a phobia of needles, wouldn't take anesthesia.
I severely doubt you didn't. Mostly because I know you to be a sane and normal person.