Son-of-Ozzy Jack Osbourne has multiple sclerosis, and learned about the diagnosis just two weeks after his daughter was born, he tells People. "I was just angry and frustrated and kept thinking, 'Why now?'" the reality-show star, 26, says. "I've got a family and that's what's supposed to be the most important thing." People notes that MS, which affects the central nervous system, can impact muscle control, vision, balance, and more; some are left disabled while others experience only slight setbacks. (More Jack Osbourne stories.)