Everyone has that one snake...

[Bogertophis]

A friend of mine gave me a Lesser that had plenty attitude because they were afraid of him but it was probably because he wasn't handled ever. He still tries to see if he can eat my forearm from time to time but its a feeding response and he's calmed way down. His feeding response is ridiculous whether live or thawed.
I'm fostering a fire killer bee from the same friend cuz she became super snappy... Like rapid firing. She's so much calmer now. I believe its due to the environment. Multiple dogs and the smell of the dogs plus constant traffic on location. I have them both in my rack and on a consistent feeding schedule in a separate tub, she's calmed down drastically... Hasn't snapped at me once!

I can't imagine it's the smell of dogs, as I have dogs and no snappy snakes (both for many years), but maybe the constant traffic, or just their luck? Some also swear
that snakes can "smell fear"- I don't really believe that, but you did mention they were afraid of them, so? (& I can't say I've ever been afraid of snakes, so who knows?)
Like you, I've taken on snakes that others were afraid of, and they became calm with me too.