So I have come to notice lately that I can NOT say thank you to someone I'm close with (family/friends) I really don't know why. This is not the case with people I don't know. When I'm dealing with a stranger I'm EXTREMELY polite (please, thank you, yes sir, no sir). And the only time I ever say thank you to family is if I do it in this stupid voice that makes it sound like I'm joking. It's starting to aggravate me. Comments? Suggestions?