First things first: This prequel spin-off of The Big Bang Theory isn’t as bad as the trailers made it look. Of course, it would be hard to maintain that level of awful. Actually, by putting most of the first two segments of the pilot in the trailers, the show prepared audiences for what was to come, which is kind of a clever way to lower expectations.

The premise is straightforward: Sheldon Cooper, the genius physicist played by Jim Parsons on the hit show, is portrayed as a child, growing up with an evangelical family in rural Texas. Parsons does the voice over narration.

The problem is harder to pin down. One glaring issue is the writing, as apparently many of the writers of the clever, intelligent BBT didn’t make the trip over to the spin-off. They have a food fight three minutes in and do a bit on Sheldon’s testicles not descending until he was 16 years old (seriously) at the five-minute mark.

But the problems go deeper than script hackery. Even if the show had brought over the entire Big Bang staff, this spin-off wasn’t going to fly.

There’s the dependence on child actors. The pre-teen Sheldon is the main character, and nine-year-old Iain Armitage does a good job of channeling Parsons. The kids playing his sister, brother and classmates aren’t quite as well cast.

It’s not so much the acting of the children, however, but rather the fact that they … are children. One reason Big Bang Theory works is that the rest of the cast is forced to cope with Sheldon’s obnoxious, grating personality, due to his status in the science department and keeper of the roommate agreement. Their attempts to accommodate him create tension that leads to easy comedy. A nine-year-old acting that way is just an annoying kid, as the constant stream of adults telling him “Shhh” attests to. There’s no reason for adults to deal with him, and they don’t, which short-circuits the comedy.

Finally, there’s the fact that it’s a prequel. We know how Sheldon turns out. He’s still a broken, antisocial prima donna who doesn’t understand how to fit in.

That means Young Sheldon is hamstrung by how much they can develop the character. Breakthroughs and very special coming of age moments, a standard with a kid-dependent show, are impossible. Instead, the show is limited to Armitage doing an eerie Parsons imitation for 20 minutes.

Time of death: A generous seven minutes.