When people say “don’t be sad, don’t be angry”, really, what they’re saying is, “I don’t want to deal with you being angry or sad, and I don’t want to feel that way, so I want you to calm down.
When people say “don’t be sad, don’t be angry”, really, what they’re saying is, “I don’t want to deal with you being angry or sad, and I don’t want to feel that way, so I want you to calm down.