If one had noticed, the early episodes of Pok魯n were of amazing quality. The rest of the series is just the results of his subconscious mind fulfilling his desires, as well as attempting to escape them. Should Ash realize he's in a coma, he would wake up, but suffer brain damage. So he has to take down all his mental barriers one by one until he can come to grips with what he is and escape his coma.
