In Wuxia stories, many top fighters practice on their own or learned from secret manuals to become greats. Little is said about them sparring or practicing real combat.
In real life, you need to spar a lot to be good otherwise your opponents will kick your butt in a real fight.
How important is sparring practice to prevent you from shitting in your pants in a real fight.
A must see video:
http://www.youtube.com/watch?v=PZLq90YeNNg