If a 20-30 year old in USA hadn't seen a Star Wars filmed I'd be really surprised.
If they had no clue as to who Barbra Walters is, I'd be not surprised in the least. That's be like expecting people of my generation to know who Will Shirer or Edward R Murrow are. I mean, I
know who they are but most of my contemporaries don't have a clue.
For those who asked, Barb was a big deal back in the day because she was the first woman in the US to chair a national TV news desk (as opposed to being just another pretty reporter). I use "pretty" as a relative term, here.
Last week, I saw a guy with an eyepatch and a gold monocle and pointed him out to Flea as one of the most awesome things I've seen, ever. If I had an eyepatch and a gold monocle, I'd always dress up as Mr. Peanut but with a hook hand and a parrot.