If you grew up in the 60's or 70's; what phrase do you find you use that other people don't understand?

You are welcomed to go further back than the 60’s but please explain the phrase for those of us who may not know what it means and how it was used or why?
My question came about when I told my daughter the phrase, In like Flint. Which came from the movie with James Colburn who played a sexy spy who could manipulate his way out of anything or into anything. It was in like Flynn as in Errol Flynn, before Colburns arrival but that was before my time.
If someone wanted to let others know that they are very much in favor with their boss or has made a really good impression on someone without having to really try, then they would say I am in like Flint.
Well please add on. I would like to learn some new ones.