Well David is David, so as you know, he's funny and irreverent and we have a laugh. We laugh about the olden days and about how different it is to do the series as old people. He has a better memory than me so the conversation is usually him being reminded of something we did and me saying, "Really? That happened? In which of the 20,000 episodes?"
It's illegal for employers to allow the age of their workers to influence decisions about hiring, promotion, and retention. There are laws banning discrimination in the workplace on the basis of age in the U.S. as well as the U.K. However, these laws don't mean that ageism doesn't exist in more subtle ways.