I was wrong. I was sure that Arnold Schwarzenegger would not run for governor of California. Tonight, to the delight of comedians and the political press, he announced that he is running.

By morning, there will be an instant poll showing support for Arnold, based entirely on name recognition, to be fairly high. No one yet knows what he stands for, other than his promise to go to Sacramento and “clean house.” What’s he going to do, pull a “Terminator” and show up naked in the capitol building while “Bad To The Bone” plays and he takes a leather outfit off of Gray Davis?

Until now, the number one issue that Schwarzenegger has stood for has been “my movie opens this Friday.” He’s always been a very effective self-promoter. On a few occasions, that promotional road has crossed my path.

Our last run-in was nearly a decade ago when he appeared on my show to promote “Junior,” a movie in which he co-starred with Danny DeVito, with whom he had worked well in “Twins.” The high concept behind “Junior” was that Arnold played a scientist who agreed to be the first man to carry a fetus in his belly. Ha ha. See Arnold become a softie as the baby grows inside him. Ha ha. It was lame.

Whenever Arnold is in movie hype mode, he has a one-track mind. You can’t budge him off message, no matter how hard you try (sounds like a prerequisite for going into politics!). But I was always determined to see if I could squeeze an answer out of him that he hadn’t given in a hundred other interviews. In this case, as we were discussing the movie, and he was feeding me the standard “dis is a funny movie” kind of lines, I asked Arnold a hypothetical question: “If biology was reversed and you could actually have a baby in real life, which woman would you want to impregnate you?”

Suffice it to say that Arnold isn’t the greatest ad-libber in the world. Thinking on his feet is not his specialty. You could hear the steam coming out of his ears as his muscle-head attempted to analyze the question and form a coherent answer.

He sputtered, “I would….um…it is….puh…da man would….hmmmfffft….” for about 15 seconds before he couldn’t contain his frustration any longer and shouted angrily, “That’s not what the movie is about!!!”

That was the last time I was asked to be part of an Arnold Schwarzenegger press tour. I had made the heinous error of going outside the lines — a violation of movie star interview etiquette. But if Arnold thought my simple hypothetical was a tough one, wait till he sees the questions he’ll get from the political press covering his run for governor. It won’t all be “ET” and “Access Hollywood” lobbing him softballs.

This could be fun. Keep an eye out for the steam.