You're right in that, Marnie. Snakes are (like ) people, too. Every one of them is different and every one of them responds in it's own way.
For example, Snakey really seems to hate it if I pick him up more than once every 2 weeks, unless he comes into my hand on his own.
Ember doesn't like me touching him at all, unless I let him come up to me.
Snap hates it when I pick her up, but calms down quickly as long as I haven't held her more than 3 times that week. She's also more calm the day after a meal, and when warm. She's extremely spastic when cold, which is weird. Runt lets me pick her up whenever I feel like it, but she stays more calm if I only handle her once a week.
Thumbelina will willingly come to my hand each time I put my hand in the tank, and I can hold her multiple times a day, 7 days a week without her hating me.
Squirt doesn't like me being anywhere near him, and for that reason I leave him alone unless I'm checking on him or helping him if he retains a shed. He's so much more calm that way.
Mama lets me pick her up when I feel like it and seems to enjoy hanging out with me, however, she's close to giving birth now, so I don't hold her. It's hard to fight the urge and any time she see's me near her she comes to the glass, and if I work inside her tank, like cleaning it, she comes up to me and slithers around my hand.

It's like therapy in a sense, you are the therapist and the snake is your patient. You need to try different things to see what fits with them and their needs.