In public, Robin Williams shared only the joy he found in life, never the sorrow. He was the same man in private, shielding even longtime friends from the darkness of depression that finally enveloped him.
"I can honestly say I never saw him in the down times," said comedian David Steinberg, who was friends with Williams for more than 30 years and toured with him for six months last year in a two-man show.
"I read about it, heard about it, but that down time he kept to himself."
When the endlessly inventive, explosively manic comedian and actor was found dead in his Northern California home on Monday in an apparent suicide, the brutal shock was felt by fans, friends and colleagues alike.
Williams, 63, who had been so open about seeking therapy - "I went to rehab in wine country to keep my options open," he joked in 2006 - minimised or hid the immensity of his pain from almost everyone.
Steve Martin, a pal who worked with Williams, tweeted he was "stunned by the loss". Chevy Chase said he and Williams both suffered from depression but "I never could have expected this ending to his life".
Last month, Williams said he was re-entering a 12-step program after months of non-stop work. After he died, his publicist confirmed he had suffered in recent weeks from depression.
It was one of several efforts over the years to overcome substance abuse. Solace from those close to him was a different matter, even as Williams faced self-described financial pressures.
Comedy club impresario Jamie Masada said he nicknamed Williams the "Doctor of Soul" because his irresistible humour could make people forget their problems. How Williams coped with his own woes, or that he had any, remained a mystery, Masada said.
"Robin always had this mask on. I could never tell that he was depressed," said the owner of the Laugh Factory clubs.
Williams was in fine form last year during his successful US concert tour with Steinberg, in which Steinberg served as interviewer and partner-in-laughs for his friend.
Cinematographer John Bailey, who worked with Williams on the independent film The Angriest Man in Brooklyn in 2012, said the role he played - of a difficult, terminally ill man - was revealing.
It "gets to that sort of really dark humour that he had, which is just below the surface", Bailey said.
Whatever distress he was feeling, Williams was invariably charming and professional, whether working for pay or charity.
Series executive producer Dean Lorey of the 2013-14 CBS comedy, The Crazy Ones, recalls his kindness towards Lorey's 16-year-old son on set.
"I remember seeing the two of them chatting together and thought, 'Gotta remember this moment'," Lorey said.
In a September 2013 interview with Parade magazine, Williams said money was part of the reason for his return to a TV sitcom.
"There are bills to pay. My life has downsized, in a good way. I'm selling the ranch up in Napa. I just can't afford it any more," Williams told Parade, adding that his two divorces hadn't cost him everything, but that "divorce is expensive".
Mara Buxbaum, Williams' publicist, said on Wednesday he had "zero" financial difficulties.
The series' fate hung over Williams when he and Steinberg last spoke a couple months ago. Williams was waiting anxiously to hear whether the freshman show would be renewed for the 2014-15 season. It was cancelled.
But Williams thought of others first. He gave and gave, and in ways both big and small. It wasn't just high-profile generosity.
Masada recalled a fundraiser he, Williams and comedian Paul Rodriguez held for a Los Angeles high school to help equip its football team. The benefit left the trio drenched in sweat because the school auditorium was stiflingly hot.
"A couple days later I got a call from the principal of the school, telling me that Robin Williams came back, brought a contractor to put in air-conditioning for nothing and didn't want anybody to know about it," Masada said.
Gilbert Gottfried was another recipient of Williams' thoughtfulness. Years ago in New York, when Gottfried was an up-and-coming comedian about to take the stage at the Improv in Times Square, Williams walked in. The club wanted to bump Gottfried, but Williams demurred.
"He said, 'I have people in the audience and I'd really like them to see Gilbert tonight'," Gottfried said.
If you or anyone you know is grappling with thoughts of suicide, there are a range of crisis counselling services available. Reach out to any of the following support groups, any time: beyondblue support service:1300 22 4636; Lifeline: www.lifeline.org.au/Get-Help/; Suicide Call Back Service: www.suicidecallbackservice.org.au; SANE Australia Helpline: 1800 18 SANE (7263).