"Have you ever watched a crab on the shore crawling backward in search of the Atlantic Ocean, and missing? That's the way the mind of man operates"

This quote by H. L. Mencken is a metaphor for how the human mind works. It is recommending that the mind of male is frequently searching for something that runs out reach, like the crab searching for the Atlantic Ocean. The crab is not able to find the ocean, and likewise, the mind of man is frequently unable to find what it is looking for. This quote is a suggestion that the human mind is often searching for something that is out of reach, which it is necessary to be familiar with this and to accept that sometimes we may not find what we are looking for. It is likewise a reminder to appreciate the journey, even if the destination is not reached.