I felt that it doesn't really matter how long you knew each other, the important thing is how well do you click with those particular people at that moment of time.
Its not easy to think of wacky and fresh ideas when it comes to birthdays and these people are just awesome in it. Trust me, the ideas would get really tricky as time goes.
Knowing that this blog might be or might be not read by you guys, but again. You guys rock!