From the ArcaMax Publishing, Jokes Newsletter:
http://www.arcamax.com/news/jokes/s-14855-585740
Sandy began a job as an elementary school counselor and she was eager
to help. One day during recess she noticed a girl standing by herself
on one side of a playing field while the rest of the kids enjoyed a
game of soccer at the other.
Sandy approached and asked if she was all right.
The girl said she was.
A little while later, however, Sandy noticed the girl was in the same
spot, still by herself.
Approaching again, Sandy offered, "Would you like me to be your
friend?" The girl hesitated, then said, "Okay," looking at the woman
suspiciously.
Feeling she was making progress, Sandy then asked, "Why are you
standing here all alone?" "Because," the little girl said with great
exasperation, "I'm the goalie!"