Of course it’s possible to know what is and isn’t appropriate - those views might be skewed by your early experiences but assuming you’re an adult you can choose for yourself what is appropriate and what isn’t in terms of how you treat others and how you let them treat you. You may have work to do in overcoming beliefs about what you do and don’t deserve from others but you can know what’s ok and what isn’t.you cannot know what's appropriate and what's not.