Glow Stick Letters

We love glow sticks.  They are super cheap fun.  I usually have a stash of them hidden away.  The morning after one of our glow stick parties.  Coda came to me with four glow sticks and showed me all the letters he could make.  There was no prompting by me.  I did not tell him to make letters with glow sticks, nor which letters to make.  Téadora was super excited when Coda made a "t", because as we all know, the only reason he made the "t" was for her. :)  Had this been a year ago, we would have been sitting at the table doing our "school work", I would have been forcing Coda to print his letters and prove to me that he knew which letters were which.  Needless to say, I have no question in my mind that Coda recognize his letters and form them.