What a lovely story. When my Grandson was little, he used to love to ring my front doorbell, a lot!! I would chide him for this and he decided he would call me Nanna Ding Dong. I can't tell you the strange looks I've had over the years when he would call out that name in any crowded place. x
^
My mate also changed his name by deed poll, Rowan. His birth name was Freddy Fudpucker and he got so fed up of being the butt of jokes that he changed it..........................to Peter. :-)