My dad was one of 15 children, and the youngest of 8 sons. When he got to first grade, as it was in the late 30's in rural South Carolina, he walked to school with older siblings and was taken to class and dropped off. Well, when the teacher asked his name, he simply told them his name was Tom. The teacher seemed somewhat confused, and after checking it out with the principal, the first grade teacher told my dad he couldn't possibly be Tom. The reason this was not possible is because one of his older brothers was named Tom, and was already enrolled in school.
At that point in time, without a name for the new first grader, he was called "Mutt" because he resembled a little "mutt" dog who was just a mixed up breed. This was his name through his adult life.
As it happened, my dad had an older brother named Halley Cleveland who hated his name, and was too embarrassed to claim that name, so he told his teacher in first grade his name was Tom. Not knowing anything different, the teacher, nor any one else questioned the validity of the name. So, when my dad got to school, the family learned that my dad's brother H.C. was known as Tom.
Last year, my "Uncle Tom" passed away, and at his funeral, my aunt told my dad, "Mutt, you can have your name back now. Tom doesn't need it anymore!"
-Susan L., Morganton, NC