"The first time I was on this show I was 13 years old; it was 1998 and I was so, so nervous, because for me - and still for me - coming on this show is like you've made it... That's really the truth... Coming on this show has been kind of like the milestone of my career every time... Thank you for everything Dave! There's never going to be anybody like you." Actress Scarlett Johansson expresses her gratitude to departing U.S. talk show veteran David Letterman for supporting her career from the start. The TV personality will step down as host of The Late Show later this year (15).