Drew Barrymore is getting the ultimate surprise from David Letterman! On Monday's episode of , Letterman shows up to surprise Barrymore in honor of her 46th birthday.The sweet moment happens when an excited Barrymore believes she's on a Zoom call with Letterman, only to have the TV personality walk out onto the set of her show.«I'm so grateful that you're here,» Barrymore tells Letterman through tears in the clip, which aired exclusively on Entertainment Tonight.«Let me tell you, something.