With the upcoming 13x06, not to mention its cousins 6x18 and 8x11, I'm reminded how much Dean loves to dress up. Are there any other instances where he's excited to dress up as something - even just something mundane?
I think his excitement to dress up comes from the excitement of that thing more than just an overall love of dressing up. The other times he’s been super excited to put on a costume it’s because he loves the thing he’s dressing up as like in 7.12, he’s excited about the Untouchables and Elliot Ness so he’s super excited to get to play a role with him:
In 6.18, again he loves cowboys so he’s excited to get to dress up and be a cowboy for awhile:
Look how smuggy and smirky he is what a cutie. And in 8.11, it’s because he’s excited about LARPing. Throughout the entire episode, he’s been excited about the idea of LARPing and when Charlie tells him he has to dress up to blend in and be able to walk around with her:
That’s the face of an excited man, and we get another let me check myself out in the mirror scene:
He does dress up at other times but there’s not really any indication that he’s terribly enthusiastic about it like in 9.13 when he has to the lunch lady:
And in Night Shifter, he dresses up as a tech guy, and then gets out of the costume as soon as possible:
You could make a case for him enjoying the dress up in 12.07
because of the way he’s playing it up with the douchebag sunglasses and because we know Dean had a childhood fantasy of being a rock star (9.07)
which the episode reminded us, when Sam asks skeptically if Vince is acting out some rock god fantasy:
but sadly there’s no accompanying montage or overt scene about his excitement like there are for other ones. Another one is when he plays a gym teacher in 4.13 because clearly he’s having a lot of fun doing that
but again, I’d say it’s more about playing a role and having a good time than about the actually dressing up. I don’t think he has a particular excitement to wear the shorts and polo shirt so much as to inhabit a role and just have fun for a minute rather than the normal drudgery of their work. I think Dean does enjoy dressing up, but more than that I think what he really likes is getting to enjoy some of his interests without fear of judgement (because it’s for the case) and/or because he gets to enjoy playing a part that has nothing to do with monsters or being responsible for someone or the bigger picture.