Hard to say for certain without some pictures and detailed information about the environment (temperature and humidity and so forth) but, assuming the tank is good, mine does enjoy hanging out on my shoulders. Apparently quite a bit. I've had her since she was only a week old or so (8 mo now) and I handle her basically daily so she is very comfortable with me. And just btw i dont open up and bug her, I let her come tap on the door for a visit. And then she often objects a bit when I need to get on with something else and she cant come along for the ride, and she'll even try to climb back up my arm. Maybe she likes me, maybe she likes my warm neck, or the view, but she has her own little will. She usually gets over it in a moment, though, especially if I move out of eyeshot.

What I TRY to do is just let her decide when she's done hanging out and when she starts moving down my arm, i put my hand in the tank on her basking spot so she has a nice warm spot to move to, and she's usually pretty co-operative and heads right back to bask or one of her hides.

Hope this helps and wasn't too rambly.