I wouldn't use "mean" to feel "guilty" although "guilty" would actually have been a much better word than "mean" in the original. "Mean", to me, is used either for someone's behaviour when it's not nice, or when they don't want to spend money.
I don't like that boy at school. He's mean to me.
The sandwich only costs $1 but he's too mean to pay even that!
Student or Learner