I'm always puzzled by the assumption that just because continuity exists among different works, it makes each individual story incomprehensible on its own.
I think this mostly comes from people having bad experiences with other works in the past that do get so bad they are incomprehensible on their own.
Using comic books as an example, if you are a fan of the Batman tv series and then jumped in during a random point in the middle of a major 90s arc like Knightfall it would have been horribly confusing. Some, though certainly not all, of the Star Wars novels have had this problem. Jumping into the middle of a major epic fantasy series like the Wheel of Time or A Song of Ice and Fire would not be a fun experience either, nor starting Lost at season 3 or the recent Battlestar Galactica at season 4 or a season of 24 at episode
You can avoid confusion these days by using the Internet.
Not really the same thing. You can get a "just-the-facts" synopsis of the story so far, I suppose, but you're not really going to appreciate the emotional impact of the story if you haven't fully experienced the previous chapters. "Oh, so this character died and this other character, that I read about on the internet, was finally reunited with his long-lost love, who betrayed him before. Yeah, this really means a lot to me without having actually watched (or read) the earlier installments."
The plot is just the bare bones of any story. It's the flesh and blood that gives it feeling.
(Besides, you shouldn't have to do homework just to enjoy a comic book or Star Trek novel . . . .)