In a reminder that shadows fall over the lives of the rich and famous, comedian Jay Leno has revealed that his 77-year-old wife, Mavis, suffers from dementia. On Friday, Leno cited dementia as the reason he was seeking a conservatorship of his wife’s estate, according to NBC. “Unfortunately, Mavis has been progressively losing capacity and orientation to space and time for several years,” the petition for the conservatorship states. The petition wants the court’s permission for Leno to develop a plan for her will that Leno believes his wife would want done if she could. Jay Leno has reportedly…