Or you've read more than 1000 Wookiepedia articles.
It basically comes down to what depth you absorb of the setting. The issue is that the "campaign setting" is not props, but that's what 7-9 directors treated it like.
And even though the Jedi powers are way OP, the Gennedy Clone Wars shorts are possibly my favorite thing EVER done in the Star Wars universe.
But as a general rule? You can be a fan of any part of a series and your fandom is completely legitimate. If you know all the details of three movies that puts you head and shoulders over someone who watches everything both uncritically and superficially.
I mean, you like what you like -and I'd say it's a question of depth of "liking" (knowing the lore, etc) rather than being comprehensive (liking anything that has 'star wars' written on the label).
Example: I'm a huge Star Wars fan.
But I don't much like RotJ.
Or Episodes 1-3.
Or Episodes 7-9.
Or a lot of their other properties.
(Clone Wars is amazing, there are major exceptions)
So, if I don't like the majority of the stuff out there, then how am I still identifying as a huge fan?