According to Biblical genealogies found in the gospels there are 42 generations between Abraham and Jesus. Christians contend that Jesus is the answer to 'the UltimateQuestion of Life, the Universe, and Everything'.
42 could be considered an example of truth being stranger than fiction*.
In addition to be the Ultimate answer to the ultimate question of the meaning of life, the universe and everything, it is also short hand to refer to 'Life, the Universe, and Everything.'
As in "How's your 42?" or "What's new in your 42?"
Or even "Never mind what my 20 is, where in the 42 are you?"