There's nothing to understand except that you - a sane, logical, intelligent person in the twentieth century - are allowing yourself to be influenced by primitive witchcraft, by black magic!
10 seconds sound clip from the The Adventures of Superman - The Mystery of The Walking Dead classic radio series.
You can hear this line at 00:13:26 in the radio play.
Quote context
[...]
- He isn't dead! I know he isn't! He isn't dead, Clark!
- You don't understand! They think he's dead! They just think that!
- Lois, look at me. Look at me, I said. What's happened to you? Are you losing your mind?
- Clark, please! Try to understand...
- Now wait a minute! Just let me tell you something!
- I spent a lot of time in Krishna's so-called Temple of Truth getting the story.
- And I saw an awful lot of things that couldn't be explained.
- This man has a kind of - power.
- Well, sure! That's what I'm trying to tell ya. The power of suggestion!
[...]