How long do most movie careers last?

I was listening to the Thought Spiral podcast. Comedian Andy Kindler talked about his early attempts at being a singer songwriter. He seemed hurt that no one supported him in that endeavor. Josh "Elvis" Weinstein pointed out that Kindler has had a thirty-year career in comedy, something that rarely happens in popular music.

With movies, I've noticed, looking at imdb.com, how many people have one or two credits and go for years between jobs---people who made one movie in the '60s, one in the '70s, and that was it. Each is a major achievement no matter how inconsequential it seemed to everybody else.

Then there are the successful ones. I'm mainly interested in the extreme low end of cinema, like Ray Dennis Steckler who worked various jobs--he was a janitor at one point and was manager of a furniture store as I recall. Herschell Gordon Lewis quit film and went into direct marketing. Dean Stockwell was and still is a successful actor and has been since childhood, but I read that he gave up and became a realtor when was called back to star in Quantum Leap.

The sad cases are people like Ed Wood, Jr, who should have given up on movies but didn't.

Alfred Hitchcock told Francois Truffaut about the time he ran into his old boss, the guy who gave him his first job in the British movie industry, working as a location scout. They pretended not to know each other.

I've thought about all the film students going into debt to get a degree in film. Most want to be movie directors, but how many people in their 20's direct movies? They'll be forty before anyone trusts them with the amount of money that goes into a movie, but I didn't really think about the other end of it----it'll take decades to build a career if you can do it at all, then you'll find yourself washed up in seven or eight years.

That's not really true, of course. There are TV commercials, industrial films, TV shows. Do they still make After School Specials? But you don't have to go to USC to do that stuff.

But what do I know.

Andy Kindler just landed a big movie role, by the way.