Birthdays are a time for family to pretend they care. Your siblings who drive you nuts all year are saints for a day, in an attempt to convince you to act accordingly when its their turn to have their face shoved in a cake.
But revel and enjoy in your siblings being forced to at least show some modicum of respect on this day, and bask in lording it over them until midnight, because then all bets are off.
Look here for more Happy Birthday Memes with animals. Your pets have no concept of time passage or birthdays so they love you unconditionally all year round.