The 39-year-old Kerr notched her 19th career tour victory by winning April's LPGA Lotte Championship in Hawaii, and last week finished fifth at the Thornberry Creek Classic.
She is also in line to make her ninth U.S. Solheim Cup team and sees no reason to lower expectations.
"I honestly think it's desire," Kerr told reporters on the eve of the U.S. Women's Open when asked about her longevity. "I love to practice, I love to compete and win and have a chance to be contending and it's a rush.
"Golf was the first thing I ever fell in love with and it's a relationship that you can have for a lifetime."
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Last year youth ruled women's golf, but 2007 champion Kerr and other more mature players are fighting back.
In 2016, with Lydia Ko, 18, Brooke Henderson, 19, and Ariya Jutanugarn, 21, leading the way, the average age of LPGA Tour winners was a startling 22.3.
This year through the first 16 events the average age was 26.3, not counting 24-year-old Danielle Kang's triumph at the KPMG Women's PGA major and last week's Thornberry Creek win by 35-year-old Katherine Kirk.
"I feel like as long as I feel like working at it, feel like training and trying to keep my body fit ... you can play for as long as you want," the 14th-ranked Kerr said.
"I've won many times in my 30s, and when I was 39 now, and I want to try to break some of the stereotypes out here, win in my 40s and 50s. Why not?"
Kerr said she has long idolised World Golf Hall of Famer Juli Inkster, who amassed 31 career wins, including seven majors. Inkster won her last event at age 45 and her last major at 42, and does not doubt what her fellow American can do.
"Cristie's wired a little bit like me on the golf course. She's feisty. She shows her emotions," U.S. Solheim Cup captain Inkster told reporters. "She has a real passion for the game of golf.
"She doesn't mind putting the time in. She loves to play. And that's 90 percent of the battle when you get to a certain age. You have got to want to play and you have got to want to be good.
"She still has that. She still thinks she can be number one in the world. I don't think there is any reason why she can't be."
(Editing by Greg Stutchbury)
