4. They post sappy birthday messages online
Can't resist gushing about how wonderful your kid is every year on his birthday? Neither can Reese Witherspoon. She wrote, "Happy Birthday @deaconphillippe! Fourteen years ago you came into my life, and have made me laugh and smile everyday since. I love your kind heart and your joyful, adventurous spirit. Hope you have the best day ever!! Love, Mom"