I can only think of negative emotions where the feeler can’t handle them in a controlled way.
E.g. getting angry and screaming and/or hitting things.
For an adult, avoiding childish behaviour when angry would be cursing and at the most, raising ones voice.

This however does not apply to emergencies and such. There will always be room for angry screaming if the situation demands it.

Being a martyr is another example. Having something go against you and proclaiming you are a victim is childish. Grow up and own whatever happened.