Pet Peeve of the Day:
People who don't RSVP. How hard it is? Pick up the phone and say "no, I'm not coming". I promise you're not going to hurt anyone's feelings. By not doing it you're just bugging them as they're probably waiting on numbers for seating assignments, caterers, favors, and the like. Trust me, I plan events for a living! It is a real pain! You can send an email or call and leave a message in the middle of the night if that makes you feel better, or just make up a stupid excuse. It just matters that you follow through when someone extends an invitation your way! Be considerate people as you go forward in your day today.