Maryanne Larkin says R U OK? Day is a gift her late husband left to Australia before he died.
The suicide prevention charity marked its 10th national action day on Thursday with a 500-strong public event at Barangaroo in Sydney.
It was a far cry from the 30 people present when founder Gavin Larkin held his first function in 2009.
"We had the first R U OK? Day in our living room at home," Maryanne told AAP.
"Some years earlier Gavin lost his dad to suicide so we witnessed first hand how devastating that could be and he didn't want that to happen to anyone else."
Thursday was a bittersweet moment for Maryanne who said Gavin - who passed away in 2011 - would have been "amazingly proud" and grateful that people were continuing to ask each other if they were OK.
"Now we have the tools to have an open conversation that's not stigmatised - it's a gift he left us," she said.
The R U OK? charity has just wrapped up a six-week tour of regional Australia teaching people how to navigate conversations when someone says they're not OK.
With drought gripping much of the country, charity chief executive Brendan Maher says people need to be ready to help those who are struggling.
"The answers are probably going to be 'No, I'm struggling, I'm just keeping my head above water, I'm just getting by,'" he told AAP.
Mr Maher said people needed to be ready to listen.
"I was in Tamworth at a regional forum and one farmer told me about how hard it was hearing the drought," he said.
"When you walk out to your paddock and hear your stock bellowing because they're hungry and you're giving them just enough to keep them alive - he said that just rings in your ears."
Mr Maher said rural areas, which have fewer services than the city, rely on their communities to keep an eye on one another and listen to those kinds of stories.
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Australian Associated Press