Things that make me go, HMMMMMMM

As the Apostle John was recording the events of Jesus' resurrection, he mentioned the Apostle Thomas and noted that he is also known as Didymus, or, "the Twin."  If John had done this once, it would be an interesting piece of trivia.  

But John doesn't write this once.  He writes it THREE TIMES -- John 11:16, John 20:24, and John 21:2.  This is hardly coincidental, and it goes beyond an interesting piece of trivia.

That being said, I don't know what John's point was in including this bit of information three times.  If someone has a compelling theory to offer, I would like to hear it.  But for now, it is one of those things that make me go, "HMMMMMMM...."