My situation is probably similar to Mardoch's. Years ago, I likely would have known the biggest pop songs of the day. There's probably a couple decades worth of radio hits that I know pretty well. But these days, even if something is being played everywhere, all the time... where exactly are those places? Certainly not in my house, car, or work spaces. I also don't listen to radio and don't have cable. I also don't go to malls, movie theaters, and some other types of places nearly as much as I used to (online shopping, streaming, etc, has replaced some of that). Other places I still go, like supermarkets or Wal-Mart or something, don't have in-store background music playing. I don't have a huge number of friends who I hang out with super-frequently, but even when I do, a fair number are into metal, and a good percentage of the rest are into some other weird stuff (like the soundtracks to obscure anime, for example) as opposed to the latest pop hits.
So I can't definitively say that I've never heard the Adele song. It's possible I heard it here or there in passing at some point. I've heard a few other pop songs in passing over the last few years, so it's not like I NEVER come across ANY pop songs EVER. But I can definitely say that I have no recollection of this song, and listening to the cover version didn't spark any. Like Mardoch, I don't have anything against Adele. Actually, I know almost nothing about her. I don't think I've heard any of her previous material either. But while I have nothing against her, I don't feel any particular desire to seek out and listen to her music either.