This is the real Robin Williams
In 2004, a young girl named Jessica Cole was dying of a brain tumor. Only 13, she made a request of the Make-A-Wish Foundation to meet one of her heroes, Robin Williams. He was in the midst of filming David Duchovny's House of D at the time, and invited her to visit him on-set. However, she was too sick to travel, so had to decline.
Williams, at his own expense, decided to hop on a jet and fly out to North Carolina to visit with Jessica in-person - and keep the entire thing hidden, so that the media wouldn't turn it into a publicity stunt. At first she had difficulty recognizing him due to the effects of her illness, but after he broke out some Mrs. Doubtfire quotes, she quickly figured out it was Robin Williams.
The two spent the day watching football, playing cards, and talking at length. Coincidentally, he received the call informing him that his good friend Christopher Reeve had died while there.
Robin Williams was such an inspiration that most people who are confronted by the claim he killed himself are perplexed. There is nothing perplexing about the man who never changed. Rest assured, he simply could not take his own life.