Memory gap

I got an invitation for dinner from my aunt yesterday afternoon. I was just surprise because I don’t remember something to celebrate on Saturday. She only gather the whole clan on special occasions like birthdays and anniversaries. I was trying to call her but I cant connect thru her land line. When I asked my dad about it, he told me its my aunt's birthday! I was thinking some other date! My, how terrible of me! Am I getting really old? Me and my forgetful mind!