What a precious video! I agree that Crowley is a very special snake and he totally trusts you, and that's a wonderful thing! You've worked hard to earn that trust.
I too have a wonderful snake (a ratsnake) who I know recognizes me over others and prefers me-- when I let people hold her she comes back to me even though they are being gentle. She loves to hang out in my robe in the morning, and she lets me rub under her chin. It's a real gift to earn their trust.
I have worked with parrots too, and again you have to earn their trust because they are not domesticated. And when you work hard and they pay it back with trust, it's a wonderful feeling!
Another factor in this is that some animals are calmer than others and it's just inborn personality-- so you got very lucky with Crowley. We have another BP named Lucy who does not trust no matter how much we have worked with her. We know she's having a good day when she doesn't try to bite us!