"After today, it's hard to think any differently," Mickelson said after the first round of the Deutsche Bank Championship at TPC Boston, where he shares the opening-round lead with Brian Davis.
That's because for a time here Friday, when he was paired up with Woods and 2013 Masters champion Adam Scott, visions of a 59 danced through Mickelson's head.
"Sure it did, yeah," he said when asked if the thought of shooting a 59 occurred to him after he birdied seven of the first nine holes on the par-71 course.
As he made the turn from No. 18 to No. 1, the 2013 Open champion thought he had a shot at the magical number.
"After I birdied 18, I felt, you know, I've got to shoot 5 under on the back side to shoot 59," Mickelson said. "There's some birdie holes on that front nine -- my back nine, but the front nine."
Mickelson had been almost perfect with his ballstriking on his first nine, hitting 6 of 7 fairways and 8 of 9 greens in regulation. He was even better with the putter, two-putting just once on the front side (No. 12) en route to a 7-under 28.
But his chances at carding a 59 took a hit in the first hole after the turn, when his second shot on the 365-yard par-4 found a bunker to the left of the green.
Mickelson was able to power out of the sand, sticking his third shot on the green inside of Tiger's ball, but his par putt went just wide right and he had to tap in for bogey.
"Bogeying [No.] 1 hurt," he said.
He wouldn't be deterred for long. On the next hole, the par-5, 542-yard second, Mickelson hit his second shot to within tap-in range and holed that short putt for eagle.
"When I eagled [No.] 2, I thought [shooting 59] was realistic," he said.
After he settled for pars on Nos. 3 and 4, those magical thoughts of an elusive 59 quickly escaped Mickelson's mind.
"When I didn't birdie [No.] 4, I stopped thinking about 59," he said. "I started just trying to get one or two more to shoot a low round in the 60s."
He came close to getting a few more -- lipping out a birdie putt on No. 5 before settling for par, then just missing with a birdie putt on No. 7 and again settling for par -- before sticking his tee shot on the par-3 eighth to about 10 feet and then draining the birdie putt.
That vaulted him to 9 under with one hole to go: the 472-yard, par-4 ninth.
Then disaster nearly struck.
Mickelson hooked his drive off the tee, missing the fairway by a wide margin and ending up in the trees off to the right of the cart path.
After searching for a few minutes, he was able to locate the ball, ultimately punching it out of the trees to salvage a bogey on the final hole and finish with an 8-under-par 63.
"You know, I just mentally went blank for a swing," Mickelson said of the drive on No. 9.
"It happens. And I try to just forget it. It only cost me 1 shot."
Asked about his playing partner's day, Woods told reporters it was impressive, but that he thought the course was "getable."
"The golf course is really receptive and certainly getable," he said. "There are a lot of good scores out there, and most of the guys are under par today."
"I think it's one of the best risk/reward courses that we play," he said. "And I feel like there's plenty of room off the tee to get the ball in the fairway. The fairways are generous. If I'm able to hit them, which I hit a number of fairways, I'm able to be aggressive into the greens, which is the strength of my game, my iron play.
"So I think that's why I like this golf course so much."
While he knows that flirting with 59 one day doesn't guarantee he'll go low on the next three, Mickelson is confident in his game for the rest of the FedEx Cup playoffs.
"I had a couple of weeks where after the British Open, the PGA in Akron, I wasn't sharp," he said. "My game clicked again last week, and I feel like these next three weeks I'm going to play very well. I can just feel it.
"You can just tell sometimes. The game feels sharp. And mentally I have a lot of energy and I'm able to focus clearly. And that's usually when you play well."
Sometimes even well enough to give yourself a chance to do something extraordinary.
Jack McCluskey is an editor for ESPN.com and a frequent contributor to ESPNBoston.com. Follow him on Twitter @jack_mccluskey.