and now, ladies and gentlemen, here's johnny! ♪ >> johnny carson wasn't just the host of "the tonight show." johnny carson was the man that america said good night to for 30 years. >> and on my watch, johnny decided that 30 years was a great time to take a bow and say thank you and good night. >> 30 years is enough. it's a good time to get out while you're still on top of your game plan. >> johnny carson retiring in the early '90s was the great moment where a huge chunk of the ice