Using "poor dog" to describe yourself may be a self-deprecating or humorous expression. It may mean that you feel that you are relatively poor financially, or that you feel inadequate or inferior to others in some way. This kind of title is not really demeaning, but a way to describe your situation in a relaxed way.

Of course, the reasons why everyone uses this word may be different, and some people may just use it to joke or express A helpless emotion. Others may use "poor dog" to emphasize the challenges they face in their efforts to pursue a better life.