Robin Williams suffered from a brain disorder that led to dementia in the final months of his life. Originally, he had been diagnosed with Parkinson's Diseasev but his strange and erratic symptoms led to another diagnosis, this one related to dementia. According to "Robin", a new biography of Williams, the actor was tragically aware of his dilemma, as it affected his performances. He would break down crying at the realization that he could no longer remember his lines. It was a tragic fate for a comedic genius and would ultimately result in him committing suicide. For more, click here.