Dr. Strangelove, Stanley Kubrick's classic 1964 Cold War satire, hinged on this great scene between Sterling Hayden as the mad US General Jack D. Ripper, and Peter Sellars as the terribly British Group Captain Lionel Mandrake:

General Jack D. Ripper: Nineteen hundred and forty-six. Nineteen forty-six, Mandrake. How does that coincide with your post-war Commie conspiracy, huh? It's incredibly obvious, isn't it? A foreign substance is introduced into our precious bodily fluids without the knowledge of the individual. Certainly without any choice. That's the way your hard-core Commie works.

Group Capt. Lionel Mandrake: Uh, Jack, Jack, listen, tell me, tell me, Jack. When did you first... become... well, develop this theory?

General Jack D. Ripper: Well, I, uh... I... I... first became aware of it, Mandrake, during the physical act of love.

Group Capt. Lionel Mandrake: Hmm.

General Jack D. Ripper: Yes, a uh, a profound sense of fatigue... a feeling of emptiness followed. Luckily I... I was able to interpret these feelings correctly. Loss of essence.

Group Capt. Lionel Mandrake: Hmm.

General Jack D. Ripper: I can assure you it has not recurred, Mandrake. Women uh... women sense my power and they seek the life essence. I, uh... I do not avoid women, Mandrake.

Group Capt. Lionel Mandrake: No.

General Jack D. Ripper: But I... I do deny them my essence.

A reader: "Mr. Derbyshire---One group where spouses do not share a marital bed is New Guinea's Sambia. Male potency is seen as a strange power called Jerangdu. It is kind of like the Maori's manu in that it can be transferred around. If you run out of it you die. Anyway, jerangdu is found in the semen. Women are always trying to steal the man's potency so the man must be cautious. Men sleep in the men's hut and visit the wife sparingly, less they age too quickly. It gets weirder from there..."

[Derb] Thank you, Sir. Er, excuse me, guys, but don't we all sort of... believe this?