indeed , this might have been an entirely verisimilitudinous assessment of the reason behind jake carvers sudden loss of loquaciousness but , as for drisdale , the actuality was that he was desperately racking his brains trying to recall the opening lyrics to the bob dylan song , all along the watchtower , for no other good reason than that he had heard the tail end of the song on some passing strangers cars cd player that morning , and he couldnt get the ear worm out of his head .