Joseph Campbell was a really smart guy who studied myths and stories from all over the world. He noticed that many of them had similar patterns in the way the story was told, even though they were from different cultures and time periods.
Campbell believed that these patterns showed us that humans all have similar experiences and emotions, and that we use stories to help us understand them. He called this the "hero's journey" or the "monomyth."
The hero's journey is a story structure where the main character (the hero) goes on an adventure, faces challenges and enemies, and learns important lessons. Along the way, the hero also meets helpers and receives gifts that help them succeed.
Campbell thought that everyone goes through their own hero's journey in life, whether it's becoming an adult, finding their purpose, or facing difficult situations. By understanding these patterns in stories, we can also better understand ourselves and our own journeys.