A man who owns a hardware store in a New England town mysteriously disappears. Years later, the man is discovered in California. His name is changed, he has remarried, and he now has a different occupation. He claims that he has no memory of his past life. The man may be suffering from:

psychogenic fugue

Explanation:

Based on the information provided within the question it can be said that from this scenario it is likely that the man is suffering from psychogenic fugue. This is a dissociative disorder in which the individual has amnesia of their personal identity, which also includes the individuals memories, personality, and other characteristics that set them apart. Which is probably why he claims to have no recollection of his past life.