Still doesn't explain what you mean by serious. I've trained in Canada for about 15 years, and I teach. As well, I tend to practice on my own. I sweat and sometimes my body hurts from the striking I do against the Makiwara, Heavy Bags, Speed Bag, etc.
If by serious do you mean I have an interest in Karate, yes, I do. I wouldn't be asking about this style if I wasn't
At the same time, I don't know if I wanna be knocked out in my first training session, or even at all. I would prefer I not be DAMAGED. Seriousness is relative.