Williams, unfortunately, died by suicide on August 11, 2014, at the age of 63.

The actor had been diagnosed with Parkinson’s disease just a few months before his death, but an autopsy subsequently revealed he had undetected Lewy body dementia, the second-most common kind of dementia after Alzheimer’s.

It’s been nine years since Williams died, and his son Zak says it’s still ‘hard’ after all this time.

But he has also highlighted his father’s sense of humor by uploading a photo of Williams from the 1999 Mercedes-Benz Cup celebrity tennis match at the UCLA Tennis Courts in Westwood, California.

Tennis legends Andre Agassi and Pete Sampras joined Williams and fellow actor Billy Crystal for a 15-minute charity match.

Williams ditched the tennis attire in favor of an enormous t-shirt, bucket hat, and cargo shorts, which he ended up rolling up to his crotch to display his thighs, much to the delight of the audience.

At another time, Williams paused the game and tossed his racket to the floor, shouting to the other players, “One moment! I only need to prepare! “Just a moment!”

This time, he yanked his shorts up so high that the waistband rested around his armpits as the audience chuckled at his signature strange comedy.

Last month, Zak celebrated his father’s ‘joyous’ character on what would have been his 72nd birthday.

“Happy 72nd Dad!” the devoted son said, sharing a screengrab from one of his father’s most renowned movies, Good Morning Vietnam.

“I was thinking about how much I used to enjoy the look you’d give me. That naughty, loving grin that your friends and loved ones recognized as Joyful, inquisitive, and amazing.

“I will always miss you and love you!”