The 29-year-old Atlanta native won his second PGA Tour title of the season at the best possible time, clinching the second of four playoff events earlier this month to vault to the top of the FedExCup point list.
Kirk maintained that position by tying for 36th at the BMW Championship on Sunday and is one of only five players in this week's elite field of 29 who is automatically guaranteed the overall playoff prize by winning the Tour Championship.
"Obviously it's more than I could have ever expected or really hoped for coming into this tournament," Kirk told reporters at East Lake Golf Club on Wednesday ahead of Thursday's opening round.
"Being an Atlanta guy, growing up in Atlanta, living in Atlanta, and just being here this week is a huge accomplishment for me. Being No. 1 (in the standings) is just incredible.
"So I'm hoping I can play really well this week and give it my best shot to stay there."
Any of the top five in the points standings would clinch the FedExCup by winning the Tour Championship - and that quintet comprises Kirk, Billy Horschel (second), Bubba Watson, Rory McIlroy (fourth) and Hunter Mahan (fifth).
Asked whether he left any added pressure by being the marked man on top of the FedExCup points list going into the PGA Tour's season-ending event, Kirk replied: "I don't really think it brings that much pressure at all.
"With the way the FedExCup playoffs are structured, and especially here at the Tour Championship, it really just comes down to this week for the most part.
"I know that most likely I'm going to have to win this week to win the FedExCup, so it's just like any other tournament, but we're playing for $11.5 million instead of $1.5 million. So it's all kind of Monopoly money to me, I guess."
MIND-BOGGLING BONUS
The winner of this week's Tour Championship will earn a cheque for $1.44 million while a mind-boggling bonus of $10 million will go to the overall FedExCup champion.
Kirk has piled up total career earnings of just under $10 million after four full seasons on the PGA Tour and does not believe his life would be transformed a great deal should he end this week as the FedExCup champion.
"It wouldn't change much, to be honest with you," said Kirk, who broke clear of a tightly bunched leaderboard in the final round with two late birdies to clinch his third PGA Tour victory at the Deutsche Bank Championship earlier this month.
"I just won a million-and-a-half a few weeks ago, and I didn't go buy anything. I'm very comfortable financially and very happy with what I have. My family's very well taken care of. I'm not a very extravagant guy.
"I'll make sure I can afford my kids' college, I guess. It obviously would be nice and it would be a pretty incredible nest egg to have to fall back on for the rest of my life, but it wouldn't really change me or my lifestyle at all."
Kirk is bidding to become the sixth player to win the Tour Championship on his first start in the elite event, following Tom Watson (1987), Chad Campbell (2003), Bart Bryant (2005), Bill Haas (2011) and Henrik Stenson (last year).
(Editing by Frank Pingue)
