Hi Ricey, I don't know if your question 'Why does it all happen at once?' was a rhetorical one or not. But forgive me, I'm sitting here bored, so I'll assume you were serious !
It's quite simply because they are random events. Random events tend to appear to happen at once, or as some people say in 3's, neither of which is quite true.
Here's how to prove it. Take a piece of paper and draw a line on it and mark every cm exactly for say 30cm ( 31 marks ). Each mark represents the occurrence of an event and the line is time itself. In this case they are not random, but perfectly ordered or 'regular', like the ticking of a clock.
Now, on another line of the same length, try to 'randomly' add 31 marks to it, not necessarily at the ends either. In order to get it to look random, the spacings will have to be sometimes closer and sometimes further apart. Now look at the result, there will be one or two isolated events or small groups, but as a result, most of the events are now closer together in groups ! Conclusion - random events tend to occur in groups. QED
Of course, I didn't invent the maths behind this, but this is how I explained it to my kids when they were younger. I hope you like it...
What to do now ? I know, I'll go and fix the rotovator....
