When I was in high school, we were encouraged to dress up for Halloween. Some of the faculty even got into the act.
Well Winslow, that was back in the old days when things were a bit more innocent back then. Heck, every year, my homeschooling co-op would have special dress up days, but no one from Grade 6 and up did that. When I was in Grade 9, when I heard about pajama, I WAS going in jammies, but when I saw other people my age didn't, I quickly changed into regular clothes.
I will admit though, if I wasn't too old, I definitely would've gone as Radar O'Reilly last year.