Propofol was the powerful drug that was administered to Michael Jackson before his death, and helped lead to the manslaughter charge against his doctor, Conrad Murray. On 'The Graham Norton Show' (Sat., 10PM ET on BBC America), Robin Williams talked about the power of the drug and his own experiences with it.

Put quite simply, Williams was on Propofol during heart surgery, giving a pretty clear indication of its strength. "It's a devastatingly powerful drug that has to be administered in a hospital situation, and he was doing it at home," Williams said of Jackson.

He talked about waking up from the surgery, disoriented from the drug. He'd received his surgery in Cleveland, and yet when he was told where he was, his first question was, "Why?"