Why y42? What's that all about?

(speak: why 42)

You know (if not, you will shortly):
Every programmer has a bookshelf full of - well - books and many of us have books written by so famous authors like Kernighan/Ritschie, Gamma/Helm/Johnson/Vlissides, Sedgewick and Douglas Adams.
The last book features in extra large letters a friendly message by the author on the front cover: "Don't panic". This makes it outstanding!

Take a look at chapter 27 of the first book of Adams (aka "The Guide").
In a far away galaxy a computer named "Deep Thought" was programmed to find an answer to the ultimate question of live, the universe and everything. Shortly thereafter (to be exact: seven and a half million years later) the waiting ended and the doom of the answer was celebrated by the people who wanted to know (they are in for a big surprise, but see for yourself):

"Good morning" said DeepThought at last.
"Er... good morning. O Deep Thought," said Loonquawl nervously, "do you have ... er, that is..."
"An answer for you?" interrupted Deep Thought majestically. "Yes, I have."
"There really is one?" breathed Phouchg.
"There really is one," confirmed Deep Thought.
"To everything? To the great Question of Life, the Universe an Everything?"
"Yes."
Both of the men had been trained for this moment, their lifes had been a preparation for it, they had been selected at birth as those who would witness the answer, but even so they found themselves gasping and squirming like excited children.
"And you're ready to give it to us?" urged Loonquawl.
"I am."
"Now?"
"Now," said Deep Thought.
They both licked their dry lips.
"Though I don't think," added Deep Thought, "that you're going to like it."
"Doesn't matter!" said Phouchg. "We must know it! Now!"
"Now?" inquired Deep Thought.
"Yes! Now..."
"All right," said the computer and settled into silence again. The two men fidgeted. The tension was unbearable.
"You're really not going to like it," observed Deep Thought.
"Tell us!"
"All right," said Deep Thought. "The Answer to the Great Question..."
"Yes...!"
"Of Life, the Universe and Everything..." said Deep Thought.
"Yes...!"
"Is..." said Deep Thought, and paused.
"Yes...!"
"Is..."
"Yes...!!!...?"
"Forty-two," said Deep Thought, with infinite majesty and calm.

Sure "42" was not what they expected and so they riddled what it could possibly mean. To get the question to their answer they asked Deep Thought for help but even for Deep Thought it was not possible to do such a calculation - but he could design a super-computer that would eventually find the answer. And he even got a name for it: Earth.

So - seen from this perspective - "Why 42?" is the question which is the base of our existence...