Mullins -- Ireland's national training treasure
Mullins junior sparked a rare show of emotion from his father -- he was in floods of tears -- as the amateur jockey rode 33/1 outsider Nick Rockett to victory in the Aintree showpiece this month.
The sweep of the places set up his second successive crowning -- confirmed on Saturday -- as champion British trainer emulating his compatriot, fellow legend Vincent O'Brien.
At 68 Mullins will not enjoy the success O'Brien had on the flat but he will be content if he can capture the race he has yet to win, the one that stops a nation -- Australia's Melbourne Cup.
Whether the extra stables he is building at his Closutton yard in County Carlow will one day produce the elusive winner Patrick is convinced, like his grandfather Paddy, his dad will die with his boots on.
"You read of trainers retiring -- I don't see Willie retiring," Patrick said after Nick Rockett's victory.
"I just see him dying at some stage, like my grandfather; he trained till he died.
"It's not a job, it's what he is."
Willie's success is not just down to brilliance but also resilience.
Willie -- who said of Patrick's National success "this is way off the scale to have your son ride the winner...I don't think I'm ever going to have a day like this again" -- had to fight back after Ryanair boss Michael O'Leary removed his 60 horses in 2016.
Mullins's brilliance comes with a huge dollop both of humility and generosity of spirit, praising his team which also includes his wife Jackie.
"Vincent (O'Brien) was a legend of legends in racing and to have your name up against him is something you could never dream of, it's just extraordinary," said Mullins last year.
"I was lucky enough to have met him once or twice but I never imagined I could be as good as him."
'Doesn't take no for an answer'
History, though, has been part and parcel of his life dating back to Paddy Mullins's extraordinary mare Dawn Run becoming the only horse to achieve the Champion Hurdle/Cheltenham Gold Cup double.
Mullins recalled in an interview with The Guardian last year a lesson he learned from his father ahead of Dawn Run's tilt at the Champion Hurdle in 1984.
"News came through that the favourite Gaye Brief would not make it," he said.
"We were cheering and one of the journalists asked: 'What do you think, Paddy?' My dad just said: 'There, but for the grace of God, go I.'
"It brought me back to my senses.
"I never forgot what he said."
Whilst Paddy's words remained with his son so his mother Maureen taught him to be bold in his thinking.
Maureen persuaded her husband to run a mare in the United States which was rare in those days.
"So much went wrong and the mare, Grabel, was caught in quarantine," said Willie Mullins.
"But she still won this million-dollar race. It was extraordinary and down to Ma. She was the driving force."
This sense of adventure and resilience both came together when O'Leary took his horses away due to Mullins refusing to lower his training fees.
"At the time that would have been maybe a quarter of the yard and to lose the biggest owner in racing at the time -– Willie could have just consolidated and been happy with his lot," Patrick Mullins told The Irish Examiner.
"Instead he went out, he got more owners, more horses, more staff, more problems, built more stables and we're bigger from it.
"That's his mindset. He doesn't take no for an answer, he'll never be told he can't do something, he'll always try. He does think outside the box."
Mullins, a diehard Manchester United fan who says he learned from racing mad Alex Ferguson's managerial style though eschewing the fiery parts, does not just think outside the box in his job.
For in the house he keeps Jeff the ageing cockerel, who sleeps beside a rottweiler.
There is a lot of crowing for Jeff to do at the moment and it seems also for the future.