Peter Kostis no longer has cancer.
You likely already knew this because of his recent (clearly joyous) tweets about, well, being cancer free and about playing 18 holes for the first time in forever.
What you might not know is how well he battled the cancer, how much trust he had in himself and the people around him, that they would beat it together.
Kostis as you know him is an analyst for CBS and a golf instructor.
He has always been a great teacher and that bleeds through on his telecasts.
He instructed world-class players like Paul Casey, Chez Reavie, and Bernhard Langer. He ran an academy in Scottsdale with Gary McCord called the Grayhawk Learning Center -- a place where McCord used to overinflate his rates because he wanted folks to go learn from Kostis instead.
Kostis tells a great story about the 1989 Ryder Cup when he got into broadcasting by, as he calls it, "pure unadulterated luck."
He was teaching, of course, and CBS was short a broadcaster so they plucked him off the range to help with the broadcast that year. He worked the Masters the next year and has been analyzing swings on your television ever since.
Recently, Golf Digest ranked him No. 31 on its list of best instructors for 2013-14.
So last year when he had surgery for colon cancer on May 21 and the ensuing preventive chemotherapy that would accompany it, well, he didn't realize how much he had to learn.
"I don't know that anybody ever knows how good they can be at something or how well they can succeed at something until they face adversity. How you handle it determines who you are," Kostis said.
Golf is so primarily about trust. Trusting the golf swing, trusting the putting stroke, trusting your yardages, trusting the process. It seemed like such a transferrable lesson for Kostis to apply to his fight against cancer given that it was something his students were always trying to do.
"I kind of had always had that mindset, that [having a doctor me tell me I was cancer free] was going to be the conclusion of this process," Kostis said.
Kostis missed the PGA Championship in August even though he tried everything he could to be there for it. He made it his goal at the time to be ready for the Farmers Insurance Open this weekend on CBS, which he is.
What did he do in his downtime?
"I watched the telecast as if I were an announcer and what I would have said," Kostis said. "I yelled at the TV screen when the guys didn't say it."
He's a teacher at his core. He can't help it. Even when bed-ridden with cancer and watching Jason Dufner lead the field at Oak Hill, he was trying to analyze and teach.
He told me that his goal, even as an analyst, is to teach viewers at home (largely amateurs) how a golf swing is supposed to work.
"I point out what they do and how they make their swings work and I try to point it out in a fashion that the amateurs that are watching at home might be able to take something at home and apply it to their golf game," Kostis said.
When Kostis announced in early January that he was officially cancer-free and ready to return to broadcasting, there was much rejoicing within the golf world.
And though Kostis was thrilled with the results, he said the fire has been hot and the entire process scarring.
"It certainly wasn't any fun at all. It wiped me out a lot more than I thought it would," Kostis said.
His attitude has remained remarkable throughout.
That's one thing about golfers and folks who have been in and around the game as much as somebody like Kostis -- they seem to possess a preternatural ability to display patience in any situation.
I don't know if that's a golf-reflecting-life trait or if it's the other way around, but Kostis certainly possesses it.
"'I got three more treatments, I got two more treatments, I got one more treatment, I'm done.' That's the way I looked at it," Kostis said. "I feel like in these situations attitude is everything."
That same advice was on display for this article Kostis penned after his pupil Paul Casey was four strokes back after the third round of the 2008 Masters.
"What has helped Paul more than anything this week is his positive attitude," Kostis wrote.
He took the verbiage he'd been feeding his golfers for years and years and turned it around, turned it on himself while battling cancer.
Except this time the stakes weren't green jackets and millions of dollars. They were thwarting cancer or succumbing to it.
"I said 'look I'm going to put my head down, I'm going to grind through this, I'm going to come out the other side a better man and a better person.' I didn't dwell on how badly I felt at the time," Kostis said.
"That the confirmation of that what I believed finally came true was pretty special."
Sounds like Kostis has always been his own best student.