Celebrities have been sending their well-wishes to David Letterman [1] via social media this week, sharing photos, videos, and heartfelt messages using #ThanksDave. Jennifer Lawrence [2] was just one of the stars to say goodbye [3] to the longtime Late Show host, but her statement was so funny and touching that it read less like a message to Dave and more like a message to anyone who has considered making a big change in their lives, or someone who is just going through a tough time. Ahead of Dave's final show on Wednesday, Jen posted a photo of herself on Facebook [4] holding a sign that read, "Don't do this! No one is sick of you, it's all in your head." Check out Jennifer's photo above, and see the other stars who stepped out to bid Dave farewell [5] in person.