I've had pet rats, and mice as well...rats, yeah...they've got personalities too, but aside from the little field mouse we raised (formula fed with a syringe) and had to remove two bot flies (gag), I never had a mouse that was particularly interactive.
They can be. I raised feeder and pet mice. Some are more...bland...than others. But they can definitely have personalities. I was pretty bummed when my last pet mouse Bartholomew died. He was a lot of fun. It was good timing though bc he passed right before we moved to Shane's and I had to get rid of the rodent stash. The rest of them were all feeders at that point bc I had already stopped breeding in preparation for the move, so that was that. :/ Bartholomew went to the boys as well - no sense in waste. That's something I'm not so sure I could do with a pet rat or rabbit though. There's certainly a hierarchy of emotional attachment.