My wife experiences this delusion. With films or TV programs I just say that I haven’t seen them and would she mind watching again. She agrees and two minutes later she’ll ask me to explain what’s happening in this film/program she’s seen before!
With the paper we just cut down to a weekly and she started to ignore everything but the puzzles. She was a prize winning crossword puzzler but is now, in the main, reduced to just staring at them with a pen in her mouth, which is sad to see but it seems to keep her happy.