Do you know who Greta Garbo was

Of course I do, but I have no idea who does and who doesn't.

Of course I know who Garbo was, but when you say if “most people over age 50” do, I’d say no. 

It is at best unlikely that any majority of people living outside of North America and Western Europe have ever heard of her.  

Yes, I know who Greta Garbo is.

I know who she was.

I know who she is like many other almost forgotten Hollywood stars. While they were alive the world revolved around them, their every move, likes, dislikes, everything.  Now they're a faded memory in the minds of many.  Like all of us will be one day, only in the minds of a few. 

So I'm distantly related to MGM star 'Franchot Tone'  He seemed to get roles as a 'second fiddle' type of guy, often playing wing man to Clark Gable. Even though Tone was a loser of sorts, his later career included lots of television roles including Ben Casey, Wagon Train, and The Twilight Zone.