Anti-Matter

A magician was training an apprentice and was well pleased with the boy's progress apart from one thing - the apprentice was too self effacing and liked to be ever so, ever so humble. If he did something well and his master would praise him, he would blush and say, "Oh it's nothing ... probably just an accident ... anyone could do this ... really ..."

The magician hoped that the boy would grow out of it, but he didn't, and so one day, the magician stormed into the tower where the boy was working and shouted at him at the top of his voice that he was completely useless and worth nothing at all.

For a while, the boy seemed to agree but then he got angry, then very, very angry and finally, as though a dam had burst at long last, he shouted back at the magician, "I'm the best apprentice you've ever had! I work hard, I am brilliant and you bloody well know it!"