They've managed to target it at an age group, that probably anyone above thirty would relate to.
It must be quite difficult to devise a campaign aimed at most commuters. I've no idea what the average age of people travelling on the Tube is. I'd guess at early thirties. Unlike one of the other ads in the campaign (below) which refers to recent certainties, the one above hopes that most people will get the Grange Hill, Back to the Future, Swap Shop, Jaws and Swatch references.
Perhaps there's some knowledge of the average age of people travelling through certain stations. I took the first picture at Leicester Square Tube, and the second at Hammermsith.
Maybe there's ads on the system somewhere targeted directly at Baby Boomers. They might make more references to the certainty of knowing that the Beatles would always have a number one record somewhere in the world or that your Dad would say "You're not going out in that mini skirt".
However, they do manage to keep me mildly entertained until the next "big choo choo train" comes along, although funnily enough that was the only part of the first ad which I wish the creatives hadn't written!