A lost sense of humour?

Something that has been at the back of my head for quite a long time is "WHY WOMEN DON'T HAVE A GOOD SENSE OF HUMOUR(when compared to men)??.
Among the many authors i've read no one other than P.G Wodehouse has made me roll on the ground with laughter.
Even soo many comic strips including my favourite "calvin and hobbes" has been created by a man. Walt disney too was a man. Most women writers, are so expressive but find it so hard to be humorous.I don't know why.

A fellow blogger told me that may this may be because women tend to get over possessive about their faults...so they overlook the funny side of it. This could be one of the reasons.
But, i think that women are generally considerate enough and dont laugh at other people however stupid they are. For centuries women have spent their entire lives in the kitchen cooking for their husbands and children while, all their humour has gone up in the air like steam.

However, the opppsite sex have made their lives very challenging giving no space for humour in it, and at the same time act as an endless source of humour too.