This is how loose the 21-year-old Spieth was during Round 2 at The Masters Friday: He was crouched over his birdie putt on the par-3 12th hole - in the heart of Amen Corner - and started cutting up with playing partner Billy Horschel's caddie.
In the middle of the biggest, most important golf tournament in the world, staring at a putt that would have taken him to 13-under par, which would have tied Raymond Floyd's 39-year, 36-hole record for shots under par, Spieth was cracking jokes.
Spieth then missed the 10-footer for birdie by an inch. He also barely missed birdie attempts on Nos. 7, 11 and 18.
As I followed Spieth on the back nine, the crowd following him continued to grow - from two-deep around the greens to four-deep.
Augusta National senses what is happening.
We haven't seen a two-round beginning at The Masters like this ever. And as I left the course tonight, the fans walking out of Augusta National with me were saying, "I think he's going to break Tiger's four-round record of 18-under (in 1997)."
After two rounds in Woods' record-breaking Masters in 1997, Woods was 8-under and Colin Montgomerie was 5-under.
"We were a little more bunched after two rounds in 1997," Woods said Friday. (Woods went from 8-under to 15-under after the third round in 1997.)
"Jordan is already starting to separate. He's just playing beautifully. I played the practice round with him and Ben (Crenshaw) on Wednesday. And he seems really in control of his game right now."
Spieth has 15 birdies through 36 holes. The Masters' four-round record for birdies is 25 (Phil Mickelson).
I woke up Friday morning thinking Spieth would get to 21-under. I said that to my good friends at TicketCity.com (who are providing me with an incredible Masters experience), and they looked me like, "OK, big boy. Let's not get carried away."
Now, as we reflect on the day, they absolutely think Spieth can go 7-under the rest of the tournament after going 14-under at the halfway point.
"I just need to keep my head down and keep trying to hit greens in regulation," Spieth said as if wearing a hard hat and carrying a lunch pail while unscrewing the cap from his Thermos.
The great thing about Spieth out on the course Friday was that he was in total control. He never had a look of stress. He was as relaxed as a casino owner on a Saturday night.
"Who knows what can happen over the weekend?" Spieth said with a smile that almost promised more fireworks.
Spieth expects Augusta National to "speed up the greens." But no one is putting better than Spieth - the No. 1 putter in the world right now in putts by round.
At Augusta, because the greens more closely resemble a ride at Six Flags with all the humps, ridges and down slopes, especially at holes like Nos. 1, 4, 5, 6, 10, 14, 16 and 17. The hole often doesn't start until you get on the green.
And Spieth has been dominating Augusta National with in-the-zone ball-striking, leaving him with makeable birdies or tap-in pars. It's totally reminiscent of Tiger Woods' locking in and bringing Augusta National to its knees in 1997.
Charley Hoffman is doing his best to chase down Spieth and needs to be taken seriously at 10-under through two rounds - 2 shots better than Tiger through 36 in 1997.
But Spieth has one bogey in 36 holes (Hoffman has three bogies). And Spieth's one bogey came because he got pumped up on his second shot into the par-5 15th in Round 1, hit over the green, and then played cautiously so he didn't end up back over the green and in the water on his third shot.
There were no bogeys by Spieth in the second round.
And he answered Thursday's bogey on 15 with a birdie on Friday.
Spieth has already been in contention at The Masters on the weekend.
He put on a show with four birdies on the first seven holes last year in the final round, taking a 2-shot lead over Bubba Watson. Only a steel-balled performance by Watson, who answered every one of Spieth's checkmates, kept Spieth from a green jacket in 2014. Spieth has said last year's final round, 72 (leaving him 3 shots behind Watson, who shot 69) has served as motivation in 2015.
If Spieth hadn't been in this position before, if he hadn't announced to the world he wants to be No. 1 and hadn't indicated that he burns to win majors - plural - then there might be concern that Spieth would back up.
But that doesn't seem to be in his makeup right now. This is a man on a mission - just like when he helped Texas win the national title as a sophomore at the age of 19.
Now, at 21, Spieth seems like a veteran. Like the guy who's seen it all, expecting everyone's best shot. Thirty-six holes down. Thirty-six to go. And no one is having more fun at this year's Masters than Jordan Spieth.