A common mistake that people make when trying to design something completely foolproof is to underestimate the ingenuity of complete fools.

...and the Universe, ... will explode later for your pleasure.

Time doesn't necessarily happen in chronological order.

You ARE Zaphod Beeblebrox?' 'Yeah,' said Zaphod, 'but don't shout it out or they'll all want one.' 'THE Zaphod Beeblebrox?' 'No, just A Zaphod Beeblebrox, didn't you hear I come in six packs?' 'But sir,' it squealed, 'I just heard on the sub-ether radio report. It said you were dead...' 'Yeah, that's right, I just haven't stopped moving yet.

Ok," he said, "I don't like to disturb you at what I know must be a difficult and distressing time for you, but I need to know first of all if you actually realize that this is a difficult and distressing time for you.

Conceited little mega-puppy.

One nonabsolute number is the given time of arrival, which is now known to be one of the most bizarre of mathematical concepts, a number whose existence can only be defined as being anything other than itself. In other words, the given time of arrival is the one moment of time at which it is impossible that any member of the party will arrive.