Holidays aren't too hard for me to remember. I figure I should find out when I get paid time and a half when I go to work!
Birthdays are more of a problem though. Dangit... everyone has a different one!! I remember Mr Scully's, and the children's... and a couple of really close friends' birthdays... but everyone else... it's like a vacuum.
It's nice at work, because we have one thoughtful soul who has everyone's birthday up on the calendar and fills in the new calendar every January so nobody gets forgotten.
Just this week, I started plugging birthdates and anniversaries into my Contacts list so I'll get reminders - at least that way I can send an e-card or order flowers or something... and not feel like a completely socially backward and absent-minded slug.