It comes to the end of Bill Gates long, successful life, he finds himself in the Purgatory waiting room, when God enters...

"Well, Bill," says God, "I'm confused. I'm not sure whether to send you to Heaven or Hell: you helped society enormously by putting a computer in almost every home in the world, and yet you've also created some of the most unearthly frustrations known to mankind. I'm going to do something I've never done before: I'm going to let you choose where you want to go."

Bill replies, "Well, thanks, God. What's the difference between the two?"

God says, "I'm willing to let you visit both places briefly to help you make your decision."

"Okay, where should I go first?" asks Bill.

God says, "That's up to you."

Bill says, "OK, let's try Hell first."

So Bill goes to Hell. It's a beautiful, clean, sandy beach with clear waters. There are thousands of beautiful women running around, playing in the water, laughing and frolicking about. The sun is shining, the temperature is just right. The whole thing looks perfect, and Bill is very pleased.

"This is great!" he tells God, "If this is Hell, I REALLY want to see Heaven!"

"Fine," says God, and off they go.

Heaven is a high place in the clouds, with angels drifting about playing harps and singing. It very nice but not as enticing as Hell. Bill thinks for a moment and announces his decision.

"Hmm, I think I prefer Hell." he tells God.

"Fine," says God, "As you desire."

So Bill Gates is taken to Hell.

Two weeks later, God decides to check up on Bill to see how he's doing in Hell. When God arrives in Hell, he finds Bill shackled to a wall, screaming amongst the hot flames in a dark cave. He's being burned and tortured by demons.

"How's everything going, Bill?" God asks.

Bill replies, his voice full of anguish and disappointment, "This is awful, it's not what I expected at all, I can't believe it. What happened to that other place with the beaches and the beautiful women playing in the water?"

It is because it can be said without a great deal of thought, all you need to say is just "um", "er" or "ah", so easy. "Um", "er", and "ah" are what linguists call "fillers". "Fillers" help conversations continue smoothly.

Although we may not consciously realise it, in a two-person conversation, people speak by taking turns. When someone thinks it is their turn to talk, they do. Otherwise, they listen. A two-person conversation becomes like a tennis match. Inevitably there are short periods of silence as people pause to let the other person take over the speaking. But sometimes a speaker doesn’t want to give up their turn and instead wants a little extra time to think about what they’re going to say next. They use a “filler” to signal this.