One grew up the only blonde klutz in a family of dark-haired athletes. The other is a redheaded softball player whose light-haired family avoided sports entirely.
Now, at age 72, two women have only recently discovered that they were switched at birth and have been living as each other for their entire lives.
Denice Juneski, of Eagan, Minnesota, submitted her DNA to genealogy website 23andMe, KARE-TV reports, only to discover that her list of relatives were "a bunch of strangers" and she didn't match anyone she knew, not even her own mother.
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She took the test a second time, and got the same result.
"Either 23andMe made a mistake," Juneski told KARE, "or I was switched at birth."
Forty miles away in Hammond, Wisconsin, Linda Jourdeans' niece noticed Juneski's name on the results of her own DNA test - informing her aunt that she believed Jourdeans may have been switched at birth.
"I did my DNA right away, because I've got to see this on paper," Jourdeans said, revealing the decades-old secret.
On Dec. 19, 1945, at Bethesda Hospital in St. Paul, Minnesota, Denice Mary Mayer was born at 2:17 a.m. and Linda Jean Nielsen 31 minutes later.
The two were somehow switched and how it happened remains a mystery.
“We'll never know,” Juneski said, “and I'm sure the nurses are dead that probably took care of us.”
For the next 72 years, the two women lived as one another, never knowing that they were actually born into another family they had no idea even existed.
"It's a crazy thing," Juneski said. "People just automatically assume they got the right family."
Juneski grew up the only blonde among brunette and redhead siblings, not an athletic bone in her body while the rest of her family excelled.
Her dad played for the St. Paul Saints baseball team, while her older sister Geraldine was inducted into the Minnesota Softball Hall of Fame.
"Yeah, sometimes I had that sense, that I didn't quite fit in," she reflected - a sentiment the athletic Jourdeans echoed.
Jourdeans, a redhead in a family of blondes, was the only athlete and played softball into her 50s.
"Suddenly it all makes sense," she told KARE.
"I was really supposed to be another person," Juneski added.
Since they discovered the swap in April, the two have met several times and have even visited the 99-year-old mother they now share: one daughter born to her and the other that she raised.
The women retell the story every time they visit Marianne Mayer, who is now 99 and in memory care. Mayer gave birth to Juneski but raised Jourdeans.
Juneski said she considers the discovery "a gift," adding, "good things come out of it, I think."