The action legend celebrated his 70th birthday on Instagram on Sunday by sharing a selection of throwback photos. In the lengthy caption, he addressed his fans' concerns and assured them that his older appearance was simply for a movie. "Not so long ago, a lot of friends saw some recent photos of me on the internet, and they were all concerned about my health," he wrote. "I want to take this opportunity to let everyone know, don't worry! It's just a character appearance for my latest movie. The character requires me to have white hair, white beard and look old.