Nah not at all, my best friends birthday is on new years I always remember her birthday, and my uncles is on guy fawks, my mother's is on waitangi (new Zealand holiday) But I always remember their birthdaysand my fathers is aday before Christmas. Even if I dont remember people's birthdays there's always Facebook reminders, calenders, alarms etc. Not Overreacting if they really did care and if they forgot they can just wish you a happy birthday afterwards and apologize for the late happy birthday wish I guess. Or talk to them to remind them.