"The answer to this is very simple. It was a joke. It had to be a number, an ordinary, smallish number, and I chose that one. Binary representations, base thirteen, Tibetan monks are all complete nonsense. I sat at my desk, stared into the garden and thought '42 will do'. I typed it out. End of story."
In programming, an asterisk is commonly used as a sort of "whatever you want it to be" symbol. 42 is the ASCII designation for the wildcard symbol asterisk.
And since we were practically raised by computer scientists (and on a steady diet of Lewis Carroll), the number 42 will always have a special place in our hearts. But the number is also quite important from a filmmaking perspective, given the fact that it sort of describes the praegnanz principle. And to compress complex dramatic conflicts into a simple, relatable and entertaining format, well, that is indeed quite remarkable. And it is exactly what we are striving for.