It's an uncomfortable and often painful truth for many. Climbing an insurmountable mountain, whether it is a personal failing, or desire, one will start to justify their own failings. It's the human psyche after all. But what they miss is belief, a leap, faith, the fire within themselves, etc...

I like to think of Heracles. He had his twelve labours. It's a metaphor for not giving up, no matter how large the challenge is.