“I think the saddest people always try their hardest to make people happy because they know what it’s like to feel absolutely worthless and they don’t want anyone else to feel like that.” This infamous Robin Williams quote does not appear in the above trailer from HBO’s upcoming documentary about the comedy juggernaut’s life, but the sentiment is definitely present. And during a week when two beloved public figures — Anthony Bourdain and Kate Spade — have committed suicide (amid reports that the latter fixated upon Williams’ own 2014 death by suicide), the trailer packs even more of a gut punch.

Robin Williams: Come Inside My Mind does feature Williams uttering other bits of (resurfaced interview) wisdom, including “You’re only given a little spark of madness, and if you lose that, you’re nothing.” The trailer also includes appearances from Steve Martin and Billy Crystal, who offer their own personal experiences with their colleague, and his son, Zak Williams, who speaks fondly about the man behind the legend.

Overall, the mood that prevails is one revealing a tortured genius and a brilliant mind who lived to perform but was crippled with self doubt once the cameras stopped rolling and the live audience went home. It’s a stark reminder that although Williams suffered from other health problems (including, as his widow Susan revealed, a debilitating brain disease known as called Diffuse Lewy Body Dementia), it’s impossible to know what someone who seems to have it all is struggling to cope with behind the scenes.