“I think,” said Ford in a tone of voice which Arthur by now recognized as one which presaged something utterly unintelligible, “that there’s an SEP over there.” …

“A what?” [Arthur] said.

“An SEP”

“An S…?”

“..EP.”

“And what’s that?”

“Somebody Else’s Problem,” said Ford… “An SEP… is something that we can’t see, or don’t see, or our brain doesn’t let us see, because we think that it’s somebody else’s problem. That’s what SEP means. Somebody Else’s Problem. The brain just edits it out, it’s like a blind spot. If you look at it directly you won’t see it unless you know precisely what it is. Your only hope is to catch it by surprise out of the corner of your eye.”

Douglas Adams, Life, The Universe and Everything, Chapter 4