Lol I agree with this analogy! My BP always seems kinda miserable when he goes into shed. All that loose skin and the cloudy eyes can't be comfortable. He is never hissy or grumpy but he becomes very slow-moving and timid. He'll flinch and bury his head if I reach for him when he's in shed.
I totally believe that BPs have moods. Sometimes mine will be very active and eager to explore, and will crawl up to my face and on my arms and smell everything. Other times, he'll be sleepy and inactive, curl up, and go to sleep. Sometimes he is calm and curious when I reach into take him out, other times he obviously doesn't want to be touched and hides his head or jerks away. I'm sure animals have days when they feel energized and content and days when they feel bleh just like us.
OP, hope your little snake goes back to a more mellow state. He's still young and has plenty of time to calm down. It's also possible you smelled different from some scent you picked up during the day, a dog you pet, a new shampoo...etc. the day he got hissy. I've noticed that my BP seems to be unable to recognize me if I smell different.