Explain the passion? Thats a tall order. How do you explain attraction, love, contentment, addiction. These things can't really be explained. They need to be felt. In the movie Pretty Woman the character Edward Lewis played by Richard Gere has a line about opera that I think applies to snakes.
"Peoples reactions to opera the first time they see it is very dramatic; they either love it or they hate it. If they love it, they will always love it. If they don't, they may learn to appreciate it, but it will never become part of their soul."
Now it's possible that people could learn to love snakes but the sentiment is more often true than not. I remember loving the first snake I saw. I wanted a ball python the moment I first saw one. Not a burmese, not a retic, but a ball. Now I have one, I don't take him out every day, I don't obsess over him. Sometimes a day or two will go by without seeing him. I can tell you that when I shut down my computer to head off to bed, I spin my chair around and the nights he is looking back at me I smile like a child. Either way, I say goodnight snake then I look to see if my California King snake is up (not my first love but still a love) and say goodnight king snake (I don't name my pets till I have two of the same breed). On that note I will say goodnight. I will submit this post then take my BP out for a few minutes of quality time, he is up and out of his hide, and then head to bed.