"Men have the uncanny ability to find nearly anything humorous. Funny is funny, and whether the joke is appropriate or not doesn’t matter to most guys. Women, on the other hand, take offense rather quickly if they feel a subject is taboo, and they’re pretty vocal about it. Any man who’s ever worked in an office environment knows this all too well, and many have suffered repercussions from the nagging cubicle-neighbor that overheard the random off-color joke and went to HR about it. This same problem makes women hate most comedy movies guys count as their favorites." - http://www.manolith.com/2009/10/01/men-versus-women/

To add my own input here, beware to have a good time in front of a girl/your girl and not let her in on it. Whatever you thought was funny, whether its an inside joke or a quote she doesn't know, it will be ruined within minutes if she can't get in on it too...

I have a friend that I tend to exploit this with.  It's my way of torturing her.  Sometimes she will say something before I can comment, other times she doesn't realize what was said until I offer my joke.  I tend to believe I'm doing her a favor.  In her defense, she showed me a picture of the Lannister children bowling, believing it funny.  I didn't get what was funny about it, I just figured it would be what they'd be doing in this day and age instead of killing people.

A man knows everything a woman understands everything.

A primiscuous woman is often called a slut while for men this is mostly something good. This is why, no matter how many women the man has sex with, he still will have one single dick between his legs his entire life,