I would have to read those exact words in his book myself to raise an eyebrow. If anyone here has his book, please scan and post that page so we can see for ourselves. Until then, I’m skeptical.
He also says he was “offered a full scholarship” in the video posted here: http://mediamatters.org/research/2015/11/06/conservative-media-react-to-ben-carsons-admissi/206676
Again ignore Politico. Forget them. This has nothing to do with them or even Media Matters. He says it, in his own words, on TV.