Taylor Swift used to draw the number 13 on her hand before her concerts for good luck. She was born on December 13, 1989, so it’s her birthday, and she has many reasons for the number 13 being her lucky number. She has credited the number 13 with many of her successes in the last few years, and whenever she sees a 13, something good happens to her. During her "Fearless" era, Swift wrote a blue "13" on her guitar-strumming hand for good luck at her concerts. However, it appears that some of her drawings have appeared to be tattoos.