"It's almost like finding this alter ego that he has," a baffled student said.
Turns out that O'Connor has volunteered at Children's Hospital Los Angeles for the past 20 years.
That's right: the toughest teacher around spends his off-time comforting babies and cuddling sick children.
The Los Angeles Times reports the 70-year-old also gives blood and has done so since 1989.
"O'Connor has donated more than 72 gallons of blood and platelets. That enormous gift - worth well over half a million dollars had it been purchased - has been especially valuable because he is a universal donor," the Times reports. He's actually the hospital's top donor.
O'Connor has never been married and has no children of his own. Why does he volunteer? He says the answer is simple,'I don't wanna see them alone. You can't do that.'
So although O'Connor might look like a tough guy ... he's actually a softie. He asked the CBS reporter to keep that secret from his students. We have a feeling that the secret's out now.