Etiquette, anyone?

I have this thing with thank you's. I feel that if you give someone something (letter in the mail, gift, etc.), they should say thank you (if they enjoyed it) or at least acknowledge that it was received. I don't do nice things for people so I can get gratitude, but it's just nice to know that well-intended gestures were appreciated, not lost in the mail, etc. I went to a wedding a few summers ago and never received a thank-you note for the gift. I still think of that as a major faux pas. And I know some people just don't have it programmed into them to acknowledge the receipt of gifts, even if they truly do appreciate it (my husband is one of them), but I can't help but feel a bit perturbed if I try to do something nice and the recipient acts like it never happened. However, the point of this post isn't to make you feel bad if I've sent you something and you never said anything about it. Really, what I want to say is that if you've ever given me a gift, act of kindness, etc. and felt like I didn't acknowledge it, tell me! I still worry about people not receiving thank-you's from our wedding, but we do think we sent them all out, so if you didn't get one, tell me! If there is another sensitive person out there who is bitter that I've not appreciated them, forgive me. And if you never thank me, I'll probably just forgive you and continue sending things because, let's face it -- I just love writing letters.