sentences:  In 2008, Cassidy publicly admitted he had an alcohol problem.On February 20, 2017, following a performance in which Cassidy had difficulty remembering the lyrics of songs he had been performing for nearly 50 years and appeared to fall off the stage, he announced that he was living with dementia and was retiring from all further performing.He said that his mother and grandfather had also suffered from dementia at the end of their lives, and that "I was in denial, but a part of me always knew this was coming."