I'm still missing the joke but please elaborate further with a more detailed explanation, considering you said it to me I must be the one supposedly on the inside of said joke.
The reference to in the phrase "inside jokes aren't as funny on a football board" I thought was quite obvious showing that the inside joke didn't start on a football board. And since I don't know you other than on this football board, then it's safe to say you were on the inside joke. I guess I was just entertaining myself and didn't ignored the fact that I was posting the joke on a board where no one would probably understand the source behind it other than the guys in my office........which is why I typed at the end "lesson learned".........now carry on......