To be honest, he didn’t become his teacher’s disciple because he wanted to learn. The longer he follows him, the more he wants to be able to do what he does – speak with authority, heal the sick, and all the while knowing that there’s no place he can call home, at least not in this life.
He’s hoping that he can somehow absorb all this knowledge just by being near his teacher, like the way water trickles out of a leaking jar and into a thirsty mouth. It’s not that he’s lazy, but that he doesn’t think he has the faith, capacity or confidence to be able to learn everything his teacher has to offer. And he’s pretty sure his teacher knows much more than he can ever know, but if he can even scratch the surface of truth, he’ll be satisfied.
It’s not until he goes through a near-drowning experience that he finally understands that even something like faith and confidence isn’t given, but also practiced and learned.