"Understanding Women" joke

This guy is walking on the beach somewhere in California. He sees a
lamp,
rubs it, and a Genie comes out. The genie is so happy that he decides
to
grant one wish to the lucky guy.
The guy thinks about it and says, "I'd like you to build a highway to
Hawaii
because I am afraid to fly. The genie responds that this can't be done
because it would be technologically impossible considering the depth of
the
ocean and the distance to Hawaii. So he asks the guy to wish for
something
else.
The guy thinks about it and, very enthusiastically, wishes he would
understand women.
The genie than said, "Do you want your highway to have 2 or 4 lanes?"