Our pet rats were affectionate, playful, cuddly, and just about as smart as animals can be without going to law school.
If you have more than one rat, they will compete for your affection: they pretty much have to have it. You can teach them to do all sorts of tricks, not counting the ones they teach themselves.
I’ve seen people who shuddered at rats wind up, 15 minutes later, petting them and doing cozy-talk. They can have that effect on you.