In "Compassion", why does Ryan seem to take offense to his mother accusing him of smoking weed? At first I thought she was being a bit catty, but then I remembered that even though he doesn't do it often, he does have a medicinal prescription. So why does he seem offended at that statement?
He may still be ashamed of it. Just because he takes advantage of the law to use it legally doesn't mean that he thinks it's good for him. Look at alcoholics.
Because smoking weed is something she would do and Ryan strenuously denies being at all like his mother.