If you know someone who says they watched MTV as it debuted, chances are they aren't being honest. When MTV premiered, it could only be seen in New Jersey. Today is the anniversary of the premiere of MTV - August 1, 1981. Check out the opening broadcast, that led into the first video ever played on MTV, The Buggles "Video Killed the Radio Star."
A good trivia question - what was the second video played on MTV? "You Better Run" from Pat Benatar.