My general rule is: I don't walk out of movies. The last time I did so was in 2006 during the fairly wretched bar mitzvah comedy Keeping Up with the Steins -- but only because I was with a friend who wasn't into it; we were bored and I was embarrassed because I had suggested the film. I'm occasionally tempted to leave in the middle of a movie that's giving me no earthly reason to hope it will get any better, but something always keeps me in my chair. Often I'm at a press screening, where it's poor form to walk out. Even if I'm seeing a movie on my own dime, I'm usually driven by a sense of duty and completism. I like talking about movies, as you've probably guessed, and it doesn't seem legitimate to do so not having given the whole thing a chance. "Oh man, I despised Movie X." "Really? What did you think of the ending?" "I left halfway through." "Oh."

I've been doing some traveling, and am spending this weekend in San Francisco. Friday was a gorgeous day, but for various reasons I'm a bit behind in my movie-watching duties, so after exploring the city for a while in the morning, I decided to head to the theater for a double feature. The first thing I went to see was Swing Vote, which I found irritating and politically gutless but certainly watchable. My next choice: The Mummy: Tomb of the Dragon Emperor.

Now, I had, of course, seen the reviews. And I knew that Rob "Stealth" Cohen was at the helm. But I either liked or tolerated the preceding Mummy films (including The Scorpion King), and in any case my tastes in Hollywood blockbusters tend not to match up with those of the critical establishment. (Nice to meet you, I'm the guy who liked Van Helsing.) Besides, it would be a dereliction of blogger duty not to see such a prominent summer release.

So I settled in for what I hoped would be a diverting two hours. Soon, however, it became apparent that something had gone horribly, irreparably wrong. The movie was like a gag version of its (mostly) fleet, funny, wisecracking predecessors. It opened with 15 minutes of boring, labored exposition. When Brendan Fraser finally showed up, all he seemed to be able to do was mug desperately for the camera. I knew that Maria Bello had replaced Rachel Weisz, but didn't think she'd appear this bored, this helpless, like she wasn't sure if this movie was a joke, or what. The plot was a complete afterthought; everyone seemed to have forgotten that this franchise is supposed to be kitschy, clever fun. Instead, I felt like I was watching the most generic Summer Spectacle imaginable, one of those lumbering studio movies where it feels like no one -- absolutely no one -- cared a lick about whether it was actually any good, so long as it was marketable. It was boring, and incredibly stupid, and it wasn't even halfway over. My heart sank -- but as usual, I was resigned to watching through to the end.

Then John Hannah got stuck in the back of an airplane with -- I swear I am not making this up -- a vomiting yak. And it dawned on me: I don't have to be here. I'm not on assignment. I could leave right now and it won't make me a less complete person, or a less complete cinephile. It's a beautiful day and I have a standing offer to join some friends for an enormous glass boot full of beer. I could waste another hour here, or I could do something else with my time. I realized that the choice was mine. And I left.

Now, this might all seem obvious to you. And I know most intelligent, normal people know better than to waste any of their time on The Mummy: Tomb of the Dragon Emperor to begin with. But I'm learning what most smarter folks already know: loving movies, even loving Hollywood movies, even loving Hollywood movies professionally doesn't mean you have to endure every piece of crap that the studios hope will gross $100 million. Of course, I would never walk out of something and then purport to review it -- if you're on assignment, you're on assignment, and there are always worse things to be doing than watching a bad movie. But unless I'm on assignment, I don't think I'm going to bother with Beverly Hills Chihuahua.

Feel free to let me know how Tomb of the Dragon Emperor ended, in the comments. And also tell me if you've walked out of anything lately.