I know what I like, and the rest of it I just pay no attention to. Most popular culture I like is stuff from the last few decades of last century (showing my age I suppose), although occasionally something new comes along that appeals to me, but most new things I just ignore. If someone makes a reference to something I don't get, I'll Google the reference, read enough about it to get the point, then move on.
It isn't just popular culture. Humanity has multiple civilisations whose literatures go back thousands of years. There is just so much, whether books just published last week or ancient manuscripts, that nobody could ever possibly read it all, everybody has to pick out the parts that interest them and pass over the rest. I'm sure for many people there must be some hidden gems which they would have really enjoyed, except for the fact that they'll live their whole life and never once stumble upon them.
Ever since I read The Triumph of Time in high school, my favourite poet has always been Algernon Charles Swinburne. If I had lived in the second half of the 19th century, that would have been rather mainstream, hip and trendy even; in the 21st century, that makes me somewhat idiosyncratic. I don't care. (I also don't care what T. S. Eliot thought about Swinburne, in case anyone wants to bring that up.)