Quoting Phaedrus

(Originally noted a few months back in a repeat reading of Zen and the art of motorcycle maintenance, I've nothing more to add since the author of the book puts it perfectly well)

Mountains like these and travelers in the mountains and events that happen to them here are found not only in Zen literature but in the tales of every major religion. The allegory of a physical mountain for the spiritual one that stands between each soul and its goal is an easy and natural one to make. Like those in the valley behind us, most people stand in sight of the spiritual mountains all their lives and never enter them, being content to listen to others who have been there and thus avoid the hardships. Some travel into the mountains accompanied by experienced guides who know the best and least dangerous routes by which they arrive at their destination. Still others, inexperienced and untrusting, attempt to make their own routes. Few of these are successful, but occasionally some, by sheer will and luck and grace, do make it. Once there they become more aware than any of the others that there’s no single or fixed number of routes. There are as many routes as there are individual souls.