Quotations and Literature Forum

Hey, i was wondering if someone could give me a clear explanation of this quote:

It isn't the mountains ahead to climb that wear you out; it's the pebble in your shoe.

I understand it, but not 100%, just wondering if someone could give me a detailed explanation, thanks.

The pebble in your shoe brought pain to the soul of your feet. Pain sends a negative signal to your mind and causes a leakage in your pensive determination and focus on climbing the mountain. In other words pain eats away your strength and morale it makes you decrease in energy bit by bit along the way...