Ayers came up with the composite because he only had boy friends.
Correct.
‘More intriguing still, Obama seems to borrow the one girlfriend in the oddly sexless Dreams from Ayers’ experience. “There was a woman in New York that I loved,” he tells his half-sister years after the fact. “She was white. She had dark hair, and specks of green in her eyes.”
The woman of Obama’s memory evokes images of Diana Oughton. As her FBI files attest, Oughton had brown hair and green eyes. The two women shared similar family backgrounds as well. In fact, they seemed to have grown up on the very same estate.
“The house was very old, her grandfather’s house,” Obama writes of his girlfriend’s country home. “He had inherited it from his grandfather.” According to a Time Magazine article written soon after her death, Oughton “brought Bill Ayers and other radicals” to the family homestead in Dwight, Illinois. The main house on the Oughton estate, a 20-room Victorian mansion, was built by Oughton’s father’s grandfather.
The carriage house, in which Oughton lived as a child, now serves as a public library. It may have already seemed like one when Ayers visited, an impression that finds its way into Obama’s memory of a library “filled with old books and pictures of the famous people [the grandfather] had known-presidents, diplomats, industrialists.”
“It was autumn, beautiful, with woods all around us,” Obama writes of his visit to his girlfriend’s country home, “and we paddled a canoe across this round, icy lake full of small gold leaves that collected along the shore.” As can be seen from aerial photos even today, the Oughton estate also has a small lake and is surrounded by woods.’
http://www.americanthinker.com/2009/05/who_wrote_dreams_and_why_it_ma_1.html
More details here:
http://www.cashill.com/natl_general/invented.htm