help settle a debate. do snakes have personalities?

[Stormy Night]

so i know this guy. I get my rats from him. besides being a rat breeder he has over 150 BP's ( not counting all the clutches he has right now), carpets, 30+ corns. so i said something about likeing the personality of my snake, that when i open their cabinet enclosure they dont try to escape, they want to climb on me, And that when i lay down on my bed i can put the snake on the bed and it will come curl up on my stomach by its own choice. So heres the debate. HE says snakes dont have personalities and they dont think like that. that they are 100% instinctual and only sit on me for warmth. NOT because they like me or anyone else. I live in Fl...its freaking HOT all over. its not like they need to chase me down for heat. I can sit outside in the shade and let my guys play in the sunny grass and most of them will crawl back over to me and climb on me. the sun is hotter than i am...again i dont see the "only for warmth "thing. my snakes all perk up when i walk into the room. even two days after they ate...so i doubt its a hunger responce. They wouldnt eat if i tried to feed them again so soon. SO. snakes: personality or nothing but an instinctual machine not capable of thinking beyond food and warmth?