Do you play golf? If you haven't, even on the professional tours either side of the Atlantic, you will surely have seen or heard of cases where someone seemingly in control of their round, ends up having a mental wobble only to see their hopes of victory evaporate.
One of the greatest golfers of all time is Tiger Woods.
I had the pleasure of seeing him in action in Ireland both in the Ryder Cup and in the JP McManus Pro Am in Limerick.
Someone who had been struggling with form and his body's capacity to take him around 72 holes, he looks to be coming back to his best.
Rory McIlroy is someone who has occupied the world number one spot and who had also been struggling for winning form, so a realtime drama is set to unfold in the coming days as both Tiger and Rory head into the weekend as joint leaders of the latest PGA tour event in Pennsylvania.
Tiger shot his lowest opening round in two decades - but still had to share the lead with Rory at the BMW Championship in Philadelphia.
The 14-time major winner's eight-under-par 62 was his best opening round score since hitting 61 at the 1999 Byron Nelson Classic.
Rory briefly threatened to dislodge Woods before equalling the American's score.
"To shoot 29 on the front nine helps. It helps a lot," Woods said.
His season's best round at Aronimink Golf Club (named after a local Indian chief) came in the week he returned to the United States Ryder Cup team after a six-year gap in which he has battled injury and personal issues.
The 42-year-old was one of captain Jim Furyk's wildcard picks for the event. Woods ended last year ranked 656 in the world but has risen to 26 on the back of what has been a consistent and largely uninterrupted season after spinal fusion surgery.
He led in the final round of July's Open Championship before finishing sixth, then was runner-up at last month's PGA Championship.
Now Woods has revealed the secret of his recent form, revealing much of Thursday's success was down to him digging out an old putter - used in 13 of his 14 major wins more than a decade ago.
"I've been monkeying around with it at home in the back yard through the summer," he said. "It just never felt right, but it feels good now. I've hit hundreds of millions of putts with that thing." says Tiger amid further proof that much of golf is about how comfortable your mind is with your tools and surroundings!
An interesting weekend beckons!