The Big Bang Theory: Every Secondary Character, Ranked By Intelligence
Although he seems to be a pretty great guy, most fans will agree that Zack isn't the most intelligent person. While Zack has revealed that he did attend college, it's safe to say it wasn't the most prestigious institutes. Fans have seen him admit that he thought the wedding ceremonies in Vegas were fake.
He doesn't seem to pick up on sarcasm, believes Elvis is alive, and he seemed to think that Raj's laser would be able to blow up the moon. Even Penny admitted that his stupidity had become insufferable. Nevertheless, fans still love him because he does show a genuine interest in science and the boys' work.