This guy is the most stubborn person when learning something that you can find. I lent him a book on flamenco guitar (that I lost hope to recover :) and he actually run through it and learned to play it like a pro. He's short but won a position as firefighter. Now he improved his English, took a sabbatical and is touring south-east Asia with a backpack.

Probably he was just diving in his next obsesion at the time.