A doctor in her residency at St. Michael's Hospital in Toronto was not too busy to remember her old boss at a fast food restaurant and take the time to send a thank-you note three years later.

Dr. Nabiha Islam, who still lives near the Dairy Queen in Markham, Ontario, expressed her thanks to Yvonne Lavasidis for her kindness and encouragement.

"You are an incredible boss," she wrote. "I have thought of you and your kindness often. Thank you for allowing me to study for my MCAT's in the back when no customers were around."

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She passed her Medical College Admission Test and is training in internal medicine.

"I call them my kids," Yvonne told the Good News Network. "I love every one of them."

George's friend, Peter Papadimitriou, posted a photo of Nabiha's thoughtful note on Reddit, and news organizations worldwide have reposted it.

"If it brings a smile to people, I'm happy to share it," said Yvonne.

(READ more from TODAY)

Photo courtesy of Yvonne Lavasidis