McCartney’s education credentials are roughly equivalent to those of Bill Gates. And both have had about the same level of success.
I haven't heard Bill Gates denigrate the intellect of President Bush. I also believe Bill Gates is, at least, a college dropout, while Paul McCartney is a high school dropout. McCartney is clearly unaware that, while president, Bush read approximately 100 non-fiction books a year, although, he probably didn't have to go to the library to get them.