I downloaded the Discover Meditation audio, and in it they actually suggest using a mantra. This is different from the "focus on breathing" method which I have also seen suggested. If one is to use a mantra, is the meaning of the word somehow significant or could it be just any word? I think I have read somewhere that different mantras have different effects or something but I have also read that the point is just to focus on the word and its meaning has no significance. Can anyone explain this to me?