Here is my reasoning:
I read the books back in the 80's. Not sure which book it was, but I'm thinking it was, So long, and thanks for all the fish. It mentioned that there were three main questions to life.
1) Why do we eat?
2) How do we eat?
3) Where shall we have lunch?
4) ???
Add to this that it was lunchtime when the Earth was blowed up. Ford had mentioned that, "Time is an illusion. Lunchtime, doubly so."
Then throw in that I was working at IBM at the time. Arguably, one of the biggest computer companies on Earth, which we know is really a huge super computer that was working on the ultimate answer. While there, I was told that lunch breaks are supposed to be 42 minutes long. The logic was that 30 minutes was rushed, but an hour was too long. People would slow down and get out of a working rhythm. 45 minutes was a good time. It gave people enough time to eat and have a smoke. But hey, we don't want people to smoke, so lets make it 42 minutes. So, I present to you, the Ultimate Question To Life The Universe And Everything, as well as the missing 4th main question to life.
HOW MANY MINUTES SHOULD WE TAKE FOR LUNCH?
My only regret is that I never sent this to Douglas Adams.