Throughout his formative years as a leading amateur and then as a successful pro on the DP World Tour, the 27-year-old has always needed to go the extra mile.
After winning PGA Tour status, MacIntyre sensibly set up a base in Orlando – but the home of Disney is no Oban. He freely admits he quickly felt homesick.
That’s why earlier this spring he flew home for three weeks with family and his shinty playing mates.
Indeed, by then playing this robust form of field hockey he sustained a shoulder injury that threatened his return to the PGA Tour at the end of April. But he partnered Thomas Detry to finish in a share of eighth place at the Zurich Classic in New Orleans.
Mentally, if not totally physically, he was recharged and then challenged at last month’s US PGA Championship where he again finished eighth thanks to a spectacular eagle at the last.
Then at Colonial he missed the cut and split with his latest caddie Scott Carmichael. He goes through bagmen at a rate of knots.
That led to the emergency call to his greenskeeper father and, famously, Dougie answered the call.
A flurry of visa issues ensued and dad turned up at the Hamilton course without proper credentials. But, eventually, he was wearing the bib to help a player no one knows better.
Dougie was the man who had introduced Bob to sport. To his beloved shinty, but – of course – also to golf. They lived over the road from the Glencruitten course where dad works.
They would share evening games around the four holes next to their house and as MacIntyre progressed, when finances allowed, so the epic journeys would start to foster a burgeoning amateur career.
“I couldn’t play in golf tournaments as a junior because we couldn’t afford it,” MacIntyre reflected after his Canadian victory.
“I think that made me. That makes me fight and never give up.
“[My parents] gave me the opportunity, but never was I spoon fed, I was always fighting for every bit of it.”
And never has there been a more appropriate bagman to assist the biggest win of a career to date. MacIntyre knows his dad’s cut of his £1.3m winnings in Ontario will now pay off his parents’ mortgage.
“He was a caddie for the week, but at the end of the day, he’s my dad,” MacIntyre said. “The emotion at the end, it was just almost out of sheer disbelief that we did it with him on the bag.
“I mean, the amount of work that the caddies do week-in, week-out, which is an unbelievable help. And then I just do it with my dad.”