I used to do theater reviews and would sit there with a pad on my lap taking notes and looking all over the stage. Inevitably, if I had a date, she'd ask later, "How can you enjoy it when you're tearing it into all these little pieces?" What makes a play great? A fine script, great actors, and a director who knows how to bring the actors into their roles. I can tell when that's not done. There are problems you can blame on the actor and others that the director's responsible for. Poor lighting can have you squinting and bring your attention to the wrong part of the stage. Bad costumes can make the whole thing a joke. I firmly believe my knowledge of plays means I understand them better than someone who just goes and takes it in.
Okay, so what does it mean?
The first thing to get over is that one isn't better than the other. "I liked that" is a perfectly acceptable response as is "That was very good." In fact, "I liked that even though it sucked" isn't a contradiction. Take The Three Stooges. They're terrible; the movies are stupid, repetitious, and insulting. I love 'em, but they're not "good."
It also means you vary your aesthetic filter to the experience. If one approaches a 3-star Michelin restaurant in Paris with the same expectations of a trip to TGI Fridays, one is going to be very unhappy. When I was reviewing theater, I used different standards for a community group than for Long Wharf Theater in New Haven. How can you hold a part time group of actors to the same standards of one of the best Repertory theaters in the country?
This doesn't mean all opinions are created equally. People study various taste genres to develop a sophistication that allows them to appreciate it at a level denied to us who won't put in the time. If you take a three-year-old to the best restaurant in town, whose opinion would you pay more attention to: the kid's or a restaurant reviewer you respect?
Finally, why is it so important?
As a chocoholic, I'll eat and enjoy just about anything, but if you take a piece of chocolate out of a Godiva box and compare it to one from a Leonidas box (a Belgium chocolate maker), you should be able to tell with one taste why the Belgium chocolate is three or four times more expensive.