What is the theme in The Last American Man by Elizabeth Gilbert?

The American man is part stereotype, part myth. Unlike provincial young men in Europe who retreat to large cities in order to become refined gentleman, the American man leaves civilization to find his way in nature, most often in the Wild West. Therefore, the American man is nothing like the European man; he is not a gentleman, but a man. The American man was not an intellectual and had no interest in reflection or formal study.