I've been at least actively lurking in the hockey fan community for a while. Countless times I've seen people who seem to have no knowledge of hockey's past.
Suggesting that Martin Brodeur is the greatest goalie of all time when even greatest of his era (Patrick Roy, Dominik Hasek, etc) is up for debate. Let alone greatest of all time where he'd be going head to head with the likes of Tony Esposito, Glenn Hall, Jacques Plante, Georges Vézina, and many others.
Additionally, I've seen people who appear to believe that women's hockey did not exist before Manon Rhéaume's NHL debut in 1993 or women's hockey being added to the Olympics in 1998. Most hockey fans know who Lord Stanley was, however, far fewer realize that his daughter, Isobel, was a hockey player and played alongside her brothers.
The documented history of hockey goes back to the 1890s, please, hockey fans, take the time to learn some of it, at least an overview of the almost 100 year history of the NHL.