Speaking of Grant Miller, there's a cracker of a quote on his website: "He is lucky who, in the full tide of life, has experienced a measure of the active environment that he most desires. There is much to be said for a philosophy which aims at living a full life while the opportunity offers. There are few treasures of more lasting worth than the experiences of a way of life that is in itself wholly satisfying. Such, after all, are the only possessions of which no fate, no cosmic catastrophe can deprive us; nothing can alter the fact if for one moment in eternity we have really lived."
Eric Shipton, Upon that Mountain.