In a deeply fractured multi-timeline reality like the BrikVerse, it's difficult to tell which version of events "really" happened even when Humans are witnessing them directly. Some events have more authority than others, and the truths of today might be obliterated by even truer truths tomorrow.
Canon is the official version of reality at any given moment. Gaining control of Canon, whether at the local, universal, or inter-universal level, is more important than any victory, since victories and defeats can be erased or reversed by a simple shift in Canon.
Events, characters, and creations become Canon when they are remembered and, more importantly, become part of a continuity of other events - even if they never happened! An individual point of Canon (known as a Particle Canon) may be awesome enough to cause a Retkon - creating thousands of years of past backstory for itself out of thin air, for instance, inserting itself into other Canon stories long after they have ended, or change crucial details of other Particles' nature.
The most important factor to events having any permanence in the fractured timeline is the quality of pictures taken. Proper photography is so important that unphotographed events delete themselves from history entirely, as reflected in the scriptural admonition "Pics Or It Didn't Happen."
The more awesome, compelling, memorable, hilarious, or traumatic a Particle of Canon is, the more power it has to usurp or override previous points of Canon. It is widely believed that this was the cause of the great universal shattering in R. 1,977, as the Canon created by the Deadly SpaceMen compounded its own historical revision in an infinite recursion, dividing reality itself by zero and cascading into the singularity known as the Explosive Canon Ball.