Book character day

The boys' school is part of the Jazz Reading Challenge this month.  Basically, we're counting EVERY SINGLE MORSEL of reading for the sake of reaching an all-time goal of 2 million minutes as a school.  Their school typically places in the top ranks of the competition and in the end, a Jazz Player will come and read with them and do some silly things (ie throw a pie at the principal).  To kick off the week, they had a "dress as your favorite book character day."  Hunter chose to be Harry Potter.  I think we pulled that off pretty good with just the attire in our closets and some paint for the glasses.  

Now, for the best part - Cole.  Cole insisted it was "pajama" day in his class.  I suggested it was "character day" just like Hunter said and every single newsletter I had read in the past 2 weeks - but no, he was adament that it was pajama day.  I pick my fights.
I went to school that morning with Cole because I was the assigned volunteer for that morning.  As we waited for the first bell at the playground, I mentioned "I don't see very many pajamas Cole."
Cole - that's because not many of these kids are in my class.
Next, we are ushered into the classroom.  NOT ONE OTHER KID has on PJ's and I'm watching Cole.  He notices quickly and slowly and slyly, he leaves his coat on and hunkers into his chair, almost hiding under the table.  The teacher asks kids to stand up to show their "costumes" since it was hard to know who was dressed up or not.  Cole kept his head down.
When it was time to leave for the assembly, the teacher asked Cole to hang up his coat.  He reluctantly did as he was asked - came back to the line - arms hugged tight to his chest and chin down.  IT WAS SO SAD!  and yet funny - I'm telling you - that kid was adament in his decision to wear his pj's.  As he left, I mentioned quietly - "if someone asks who you are, you can say you are Max from the book where the boy stays in his pajamas the whole time."  He kinda smiled and gave me an exasperated shake of the head....
When he returned from the assembly, he looked like he had the time of his life and well, he didn't care what he was wearing.
Is it wrong that I got such a laugh from this?