Human ingenuity

One day, literally hundreds of years ago, Og the caveman wandered back to his tribe and said "I say, you fellows, I think I've just invented something. I don't know what it is, but bloody hell it's hot."
And so it was that humanity discovered fire.

Douglas Adams once said that of all Isaac Newton's ideas and inventions, it was the catflap which impressed him the most. Gravity had always been there and it was only a matter of time before someone noticed it, but the catflap - a door within a door - showed a mind of unusual lateral thinking and creativity.

The world is full of inventions and ideas like that - the stuff you look at and wonder what on earth the inventor was thinking. The best known example is possibly the old Calvin & Hobbes joke about milk: "Who was the first person to look at a cow and think ' I'm going to squeeze that and drink whatever comes out'", but there are loads more. For example, take the famously tasty but enthusiastically poisonous sushi ingredient, fugu fish. You have to wonder why people persevered with that one:
"Blimey! This Fugu fish tastes delic- erk!"
"Oh, no! Tanizaki is dead!"
"But he said that the fish was nice. I wonder if I just ate a little bit...erk!"
"Well, it's worth a try for a taste sensation, I suppose."

Some, if not most inventions have been the result of diligent investigation coupled with inspiration with at least a vague idea of an end goal. When he was trying to get a working lightbulb Thomas Edison tried hundreds of possible filaments, including cotton and his own hair to try and find something that would incandesce in the desired way. However, there are the inventions that don't follow this route - and of those some of them have no convievable logic or sense in their discovery. Take the invention of colonic irrigation. I can only assume that someone at a loose end one afternoon found they had only a pair of bellows and several pints of warm water to entertain them and the rest is history. There's so many possibilities like this. The zombie potion of mixed fish and herbs they make in Haiti? I don't even want to think about how they started researching that, let alone what gave them the idea in the first place. People licking toads to get a bufotenin high? Just how desperate do you have to be to go round sampling the wildlife in order to get your fix? ("God, man, I'm jonesin', I'm jonesin', gotta have me a fix man, I need it, I need it, I know, I'll lick that buffalo and see what happens" just doesn't sound likely, somehow. Or, on due consideration, maybe it does).

So that's today's question. Which invention or idea do you look at and think to yourself "Just what the hell were they thinking?".