Symbolism, Imagery, Allegory
Jack is all about "secret knowledge," and he thinks the Big Twitch is the ultimate in secret knowledge. So much so that he has to go all the way to Long Beach, California to get it. This is part of American mythology: going west to fulfill your dream.
Jack is "drowned" in these dreams, "drowned in West," and reborn into somebody who can't be hurt by the world in which he has to live and work (7.187). This leads to the Great Twitch, but also to a fearlessness and resolution in his search for the truth.
It's also kind of funny that Jack is so excited about having secret knowledge, and finally not having to "envy" other people that have secret knowledge. Isn't that what he always has? Isn't that what he does for a living? Isn't that what sent him hurtling west "doing seventy-five" in the first place? (7.1)