Yeah, the # 40 is mentioned alot in the old and new Testaments. It seems to be a number that symbolizes an inner preperation for something. - an ordeal one has to go through to help prepare them.
The Isrealites travelled through the wilderness for 40 years, Jonah was in the belly of the whale for 40 days I think, and Jesus was in the desert for 40 days before starting His ministry. There are other examples as well.
Every time the number 40 is mentioned, it always ties in with some sort of discipline or crisis someone went through, where they came out better in the end.