I am not a painter, I am a poet.
Why?  I think I would rather be
a painter, but I am not.  Well,
for instance, Mike Goldberg
The occupations of “painter” and “poet” are inherently linked in their place in haute couture and thus their desire to depict true art. O'Hara, additionally, links the two terms in a parallel structure and reinforces the doubling by highlighting their alliterative qualities.
Why I Am Not a Painter