My wife, Kate and I absolutely loved the series and can't wait for the next one (hopefully there is a sequel!). I would love to know what the catchy song is called and who wrote it, maybe because I am "old and grey" and still interested in life:-). If anyone has the full lyrics please send them.
Of course one big reason why my wife and I liked this series so much was that we are 75 years old and retired but still very active intellectually. It's great to see a show that highlights the contribution to society that can still be made by older people with special skills and experience. The human interest aspect showing the interactions of the characters and the younger people around them is an important part of the show.
This series is highly entertaining and very sophisticated, on a par with some of our other favourites, "Spooks" and "Hustle".