I was aged 7 or 8 when it first aired in the U.K. in 1974 and I was always deeply confused by Happy Days. I didn't understand that it was a current series, it was so un-funny that I assumed it had to be a re-run of a show from the 50s. I didn't understand why the audience acknowledged Fonz when he walked into a scene. I didn't understand how all these actors, who were clearly adults, could still be in high school. I just didn't get any of it. Clearly, it was an issue of culture shock, because the series is much-beloved in the U.S.