He is a working doctor. He does not have an outstanding background or a tragic life experience. He is just an ordinary person who grew up.
The only thing that can be said to be different is that he is a particularly gentle person, treating the elderly, children, and even some very sick patients. This is not because of his work, but because of his personality.
Such a person could actually travel through time and space, just because of that casual joke, he couldn't just accept the situation~ I just didn't expect...