I am currently reading Napoleon Hill’s Think and Grow Rich as it was recommend by several people.
One of the main lessons I have taken away is the principle “three feet from gold”. Hill shares a story early into the book about how a gold prospector during the gold rush owned a mine. Initially there was a period of success but then the gold was no longer found so after digging he can conclusion all the gold had been exhausted. So he sold the mine and moved on only to find out the people who bought the mine continued to dig and three feet from where he stopped they discovered the largest deposit of gold at that time.
This story works because everyone has moments when all seems lost and the desire to give up is overwhelming. To give in is often simpler than fighting on. In these moments I know I will think of this story to give me the strength to carry on.