It is not the distant mountains that make people tired, but a grain of sand in their shoes.

"It's not the distant mountain that makes people tired, but a grain of sand in their shoes." This is a sentence by Voltaire, a thinker known as the "King of France". People often think that external things are influencing them, but what really controls you is your heart. Nothing is difficult in the world, if you put your mind to it. In real life, sometimes it's not the great challenges that crush you, but some trivial things. Therefore, in our life, we will often encounter these negative emotions or misconceptions. These bad ideas are like gravel in shoes, which will wear our "feet" and hinder our progress.