know-it-all or nothing at all..

I think it could be easier to teach someone who knows nothing at all because that person would have the possibility to become open minded as he/she is willing to learn from other people. I wouldn't mind the know it all because according to the definition which is actually true they are kind of person who claims that they know everything and they don't usually listen or take advise from other people so why waste your time with a close minded person?

I think it would be harder to teach someone who knows it all because he might even challenge you and would even repel your ideas. As for teaching someone who knows nothing at all, i think they would be a lot more appreciative and very trusting.