Haha, I think it was two: One, that it's not that uncommon for a girl to get off in 2 minutes of oral sex (NOT counting foreplay). Two, that overall, giving a girl head is easier than giving a guy head.
I bet you're right about part 2 at least. Giving a real blow job (without excessive hand use) really seems like quite a chore. As for part 1, if you ask me, it's all in the foreplay.