Who is Daddy Watson from Suttree and what is their importance?

Daddy Watson is an old,retired railroad worker who wears a large pocketwatch. He talks as though he is still on the railroad, and probably suffers from dementia. Suttree looks in on him and cares for him. The reader does not know if Daddy is someone he has known for a long time, like the ragpicker. Daddy Watson is taken away from McAnally Flats, but Suttree sees him later in the insane asylum when he goes to see his aunt.