<P>... a towel has immense psychological value . For some reason, if a strag (strag: nonhitchhiker) discovers that a hitchhiker has his towel with him, he will automatically assume that he is also in possession of a toothbrush, washcloth, soap, tin of biscuits, flask, compass, map, ball of string, gnat spray, wet - weather gear, space suit etc., etc . Furthermore, the strag will then happily lend the hitchhiker any of these or a dozen other items that the hitchhiker might accidentally have "lost". What the strag will think is that any man who can hitch the length and breadth of the galaxy, rough it, slum it, struggle against terrible odds, win through, and still knows where his towel is, is clearly a man to be reckoned with . </P> <P> Adams got the idea for this phrase when he went travelling and found that his beach towel kept disappearing . In' The Hitchhiker's Guide to the Galaxy - The Radio Scripts', his friends describe how he would always "mislay" his towel . On Towel Day, fans commemorate Adams by carrying towels with them . </P> <P> The only entry about Earth in the Guide used to be "Harmless", but Ford Prefect managed to change it a little before getting stuck on Earth . "Mostly Harmless" provoked a very upset reaction from Arthur when heard . (Those two words are not what Ford submitted as a result of his research--merely all that was left after his editors were done with it .) It is the title of the fifth book in the Hitchhiker series . Its popularity is such that it has become the definition of Earth in many standard works of sci - fi reference, like The Star Trek Encyclopedia . Additionally, "Harmless" and "Mostly Harmless" both feature as ranks in the computer game Elite . Also, in World of Warcraft, there is a rifle that fires (mostly) harmless pellets . In the MMORPG RuneScape, there is an island called Mos Le Harmless (Mostly Harmless). Low - scoring players in the multiplayer version of the game Perfect Dark and GoldenEye 007 are awarded with the designation "mostly harmless". In the 2008 edition of the board game Cosmic Encounter, the Human race is given the attribute "Mostly Harmless". In the game Kerbal Space Program, there is an atomic rocket motor with the description "mostly harmless". </P> <P> In chapter 17 of the novel The Hitchhiker's Guide to the Galaxy, Arthur Dent tries to get a Nutrimatic drinks dispenser to produce a cup of tea . Instead, it invariably produces a concoction (which most people found unpleasant) that is "almost, but not quite, entirely unlike tea". </P>

He answer to the ultimate question of life the universe and everything is 42