In class, we learned to rate exactly how historically significant events from the past were.
"Historical significance is the process used to evaluate what was significant about selected events, people, and developments in the past. Historians use different sets of criteria to help them make judgements about significance." http://facingthepastshapingthefuture.com/teacher-guidance/teaching-learning-strategies/history/historical-significance/
Every event ranges in significance and its historian's jobs to determine that. They have to determine whether or not an event is worth sharing with others. Historians have to think about many things when they determine historical significance and weigh the overall importance of an event.
Historical significance depends on many things.....
Importance of event at the time
How widespread and lasting were the consequences of event
How much the event/incident symbolized an important issue or trend
Which group deems it important... it usually isn't important to everyone
All these aspects of historical significance deem things important but it is crucial to recognize when events aren't important enough to share with a nation. Not everything needs to be remembered, but some things certainly do in order to not repeat history. The things that need to be remembered are considered historically significant. Not all historically significant events are well known and it's our job as a human being to recognize it and do our best to share it with the world, but sometimes we remember things we really don't need to. After all, eating a really good pb&j sandwich might be important to you at the time, but I don't think the council of world leaders would really care. Meanwhile, everyone wants know if there's a new leader because it could initiate all of the things that make an event important... especially if there's a leader as attractive as Justin Trudeau.
"Very simply put. Something of historical significance is anything that had a bearing on the situation at the period of time it took place. For example, gun powder being used in a cannon for the first time changed history. so its significance was real. Another example was at the battle of Hastings 1066 the English cavalry could not use their lances at full speed as they had no way of staying on the horse when contacting the enemy. The reason..Their didnt have stirrups to help support them in the saddle. The Normans did have them. They were invented by the Mongols and slowly spread across Europe. So stirrups were of historical significance at Hasting..They helped win the battle." -Howard Prothero