The programmer side of me is seriously rebelling over this damned stupid code at work. It'd be too simple to say it ruined my weekend (as my weekends are not usually anything more than sleeping 15 hours plus 1-3 repeats of lonely staring at the wall, philosophising, or sketching at some random coffeeshop combined with travel time), but I've been stressed out over it and working on it whenever I can make myself for the whole time. I have decided that I will not leave work today until it is done-ish (which I might chicken out on if it gets to be 11pm). On the upside, it provides more impetus to think about what code and coding should be like - the simple challenge of deriving what exactly is wrong about something that's lousy without becoming crazy-polarised and picking something else because it's an opposite that's probably even worse (in this case, formal software engineering).
In brief: a framework. I assert that stories, like songs, recipes, and several other things, are not ownable. These things are fluid, cultural content - we hear them, they float around in our head for awhile, and we may share them in some altered form to someone else. When there are enough stories about the same imagined character, world, or set of events, we are presented with a difficulty - to the extent that we establish separate corridors of the mind where these things achieve a pseudoreality, how do we fit them together so we can reason about these hypothetical worlds? We could decide not to demand much consistency from these stories - we certainly can read works that don't fit with others (e.g. a fanfiction with Batman and Huck Finn on a spaceship). The high complexity and low fun-utility of that view is daunting for most purposes - while we can "fall back" to that to read a book, we want simpler frameworks. Humanity thus invents the Canon - a particular set of stories that constitute a fantasy (whether the reader decides I am trying to make a snide comment on the origin of the term in Christianity is left up to said reader - I am not sure myself). With the canon, these stories are divided into two general categories, those that are canonical (part of the imagined world), and those that are noncanonical (including fan-fiction).
This framework in place, a question: who defines canon? To some, one person or entity does, and there is only one canon. They assign this to the original author of a story or some corporate or other entity which has acquired copyright or similar rights - works by that author or entity (and perhaps those authorised) are canonical, everything else is not. I reject this - I hold that each individual has their own canon for every work they have invested themselves into (read, liked, and thought about the mechanics of within and possibly outside the stories). They may reject some works as canon (even those that come from what would be considered first sources in the perspectives above), add other stories to the canon, change details of these stories, etc, and they can share their perspectives on these matters with others.
That said, people who know their canon is rather different than what is common would do well to be cautious when conversing with others. There are, for example, works of classical music with many variant forms, sometimes by the first author, sometimes by others. One's language should reflect that there is no "true form" of this cultural content, but that a certain consensus on the most known form is in place (whether it be the original or not - Ednaswap's version of "Torn" and the original versions of the fairytales collected by the Brothers Grimm are now relatively unfamiliar while later versions are) - we are not compelled to the most common usage, but might want to mention the difference to those not expecting it; I might, for example, argue about the Daleks in the BBC series "Doctor Who", but it would be wise to tell people when I enter that discussion that my notion of Dr Who cannon is likely different from theirs (in my canon the 7th Doctor was the last we've seen so far (apart from the Valeyard)).