In reply to captain paranoia:
He also did all night phone in radio shows early in his career, he could have been “interviewing” dozens of people a night.
He had a nightly TV show for 32 years, 200 a year would be 6400 episodes, 3 guests a show gets you to 19,000.
Edit: I’ve just checked, Larry King Live, which is only 1985-2010 had 6,120 episodes.
Post edited at 14:52