“In order to understand how a college student could attend an undergraduate college for 4 years without ever being seen by any of his classmates . . .”
Obama claims to have attended two undergraduate schools (Occidental and Columbia) not “an” undergraduate college. His actual attendance at Occidental does not appear to be in dispute. At Columbia University he appears to have been a low or no profile student.
Meanwhile I have seen a documentary where dozens and dozens of people who attended Yale were willing to go on camera and say disparaging things about their classmate, George W. Bush.