I don't believe that snakes are "mind-readers", but to the extent that our nervousness can manifest in overt symptoms (such as our being restless & hurried, rather than being relaxed & empathetic) I think they pick up on that. I've never paid too much attention to a snake's normal sleep hours when I've needed to handle them, but I agree that might contribute a little stress as well.
Mostly I think empathy is the key: Even when I've had to do something a snake doesn't like, the fact that I'm being gentle & helping them feel "safe" rather than exposed & under attack- & mentally trying to feel what the snake is feeling- that's what I think matters & what they pick up on. Don't ask me how.
As far as I can tell, snakes do not have anger or hold grudges...they either feel safe with us (know by our touch that we're not a predator) or they don't. Just because they're covered with scales...don't underestimate their sense of touch. They communicate with other snakes that way too. And they certainly learn to recognize us by how we touch them. Put your voice into your hands...& when you do that, you'll forget to worry about being nipped, & then you won't be.![]()