When we got our rescue cats, a pair of seven-year-old brothers, they were very well socialised, a very polite pair. Once they realised that they'd got under our skin, their manners deteriorated. They stopped waiting to be fed, and started demanding.
And then their worst trait appeared, furniture destruction. Our armchairs and sofa had survived our previous cats, but not this pair. We'd given them a scratching box when they moved in, and for the first six months that was fine. Now, it's neglected. Furniture is so much more fun to sink claws into.