David Lee Drennan, known with deep affection as Pop, Dad, and Poppy to his family, and simply as “Doc” to generations of students, colleagues, and friends, passed away peacefully on October 31, 2026, at the age of 86. He leaves behind an enduring legacy of intellectual curiosity, unwavering service, and an immense capacity for love.

Born and raised in Fort Worth, Texas, Doc attended Amon Carter-Riverside High (“V-I-C-T-O-R-Y!”), briefly attended the University of Colorado, and went on to earn his Bachelor of Science, Master’s, and Ph.D. in Mathematics from Texas Christian University. He carried a lifelong Texas warmth with him when he moved to Norman, Oklahoma, in 1968 to teach at the University of Oklahoma. Seven years later, he found his true calling in secondary education, joining the faculty at West Mid-High School in 1975 before moving to Norman High School in 1979. In 1997, he helped open Norman North High School and taught there until his retirement in 2005.

Over 37 remarkable years in the classroom, Doc shaped countless young minds. He was the visionary founder of the Aegis program at Norman High, an accelerated, gifted, by-selection-only mathematics program that spanned 15 graduating classes, produced four Presidential Scholars, and launched the careers of future scientists, mathematicians, educators, and artists. To hundreds of former pupils, Doc was not merely a teacher; he was a foundational spark in their academic journey.

Doc’s brilliance as an educator earned widespread state and national acclaim. In 1984, he received the Presidential Award for Excellence in Science and Mathematics Teaching. He served as a fellow and summer professor with the Rickover Science Institute (later the Center for Excellence in Education) from 1985 to 1994, pioneered distance learning between Norman high schools as early as 1990, and was chosen for the National Education Leadership Program in 1997. In 1998, he became one of the first 39 educators in Oklahoma to earn National Board Certification, subsequently serving on the National Board for Professional Teaching Standards. A passionate champion of public education, Doc was also an instrumental founding board member of the Oklahoma School of Science and Mathematics (OSSM), helping steward the institution through its inception and serving faithfully on its board for more than three decades.

Beyond academia, he was a fixture on local ballfields, coaching women’s slow-pitch softball teams, serving as commissioner for Norman Slow Pitch, and ultimately earning induction into the Oklahoma Slow Pitch Softball Hall of Fame. A dedicated member of the Kiwanis Club and a faithful member of First Christian Church of Norman since 1968, he could always be found helping wherever hands were needed—mentoring youth, serving on committees, or helping out the Men’s Fellowship Group with Bean Suppers. Following his retirement, Doc dedicated his holiday seasons to the Cleveland County Christmas Store, using his sharp analytical mind to digitize their operations while spending countless hours alongside his wife supporting families to ensure every child experienced the joy of Christmas morning.

Yet for all his accolades, Doc’s greatest joy lived squarely at home. He considered himself the luckiest man on earth when he married the love of his life, Sandra, on August 29, 1965. Their devotion to one another for over six decades was absolute, steady, and the cornerstone of his world. He had a razor-sharp intellect, an infectious chuckle, and a trademark mischievous streak that kept everyone around him on their toes. He was generous to a fault, endlessly inquisitive, and quick to lend a hand to anyone in need. In his later years, he was rarely seen without Maggie—his devoted little dog, constant companion, and beloved shadow.

Doc’s legacy of love, curiosity, and kindness lives on through his cherished wife of 61 years, Sandra Drennan; his son, Daniel Drennan and daughter-in-law Melissa (whom Doc loved as his own daughter); his daughter, Leigh DeFreitas and son-in-law Jason (whom Doc embraced as his own son); and his four beloved grandsons, who brought him infinite pride: Dylan (Purdue University), Noah (University of Oklahoma), David Lee (Syracuse University), and Jason Jr. “JJ” (Durgee Junior High School).

In lieu of flowers, memorial contributions may be made in Doc’s honor to the Oklahoma School of Science and Mathematics (OSSM) or to the Cleveland County Christmas Store, continuing his lifelong dedication to learning and community care.