It really just depends on who the comment is coming from. Generally, if your getting the vibe in your gut that a person is full of shit, then most of the time, they likely are. There are certain subtleties in tone, facial expression, and body movement when someone is faking a compliment.. you usually can just tell. Where as the genuine article can be determined by earnest excitement or an otherwise touching moment from someone who doesn't regularly maker such comments. Just something you pick up with in time depending on how many assholes you manage to surround yourself around.