I'm not too bothered unless someone know's it's a special day for me and deliberately tries to ruin it or treats me wrongly on that day.
I'm a bit like toujours and I like to forewarn people beforehand. For stuff like monthly anniversaries or whatever, I don't care if others remember them as I forget them half the time, but saying "Oh hey, this happened on this day, that's great." Is sorta nice to recall.
I'm terrible with remembering saint-name days, though.. which my mom finds to be so important and I just guess I don't so it doesn't stick in my memory.
Anyways, I'm rambling now.