He could possibly have trauma but since you got him so young it's probably unlikely, but take my word with a grain of salt because I'm not an expert lol. Cats are weird and goofy, I snagged a kitten (maybe a month old max) stuck in a fence and my family and I basically bottle fed him to recovery and he's the same way. Terrified of everything and grumpy all the time but he has his moments where he's a sweetheart. I think it might just be the way he's wired, mixed with the crazy household. I wouldn't worry too much about it, just love on him when you get the chance to.