When it comes to celebrity antics, sometimes we think we've seen it all . . . only to get surprised again with more "Um, what?" moments. From Lady Gaga hiking in heels to Shia LaBeouf hitting the red carpet wearing a paper bag over his head, we've learned to always expect the unexpected when it comes to stars. While these moments are often a bit over the top and can be hard to relate to, they make for some hilarious entertainment. Wouldn't you agree?