I like to think of him as a retired cop in a way- his skills might be a bit rusty (hiding in that hut for so long) but he's still got his piece (ie lightsaber) and still remembers how to use it when he needs to.
That and ol' Georgy boy probably just through it in there as a throw-a-way line to help reinforce the crazy, old hermit idea he was trying to push with Obi this early in the film.