I'm not a war historian, or a big war buff (but my friend Tom is). It's just an area of casual interest for me. Most of what I know comes from the History Channel and stuff I read elsewhere, like Veterans Affairs Canada's Canada Remembers series. I've noticed that unlike in Canada, there's hardly ever any mention of WWI in the US. I haven't dug into the reasons why that would be yet.
Perhaps what makes it a source of national pride are of some of the notable events that Canadian troops played a major part in, or the fact that nearly 10% of the Canadian population at the time served in WWI (pretty significant for a small country).
The Great War was also a landmark in Canadian national development. In 1914, Canada entered the war as a colony, a mere extension of Britain overseas; in 1918 she was forging visibly ahead to nationhood. Canada began the war with one division of citizen soldiers under the command of a British general, and ended with a superb fighting force under the command of one of her own sons.
Whatever the reason, and wherever you're from, take a moment to remember those that battled, and those that fell 90 years ago in WWI and also in more recent conflicts.