Grew up playing golf at River Creek Club in his longtime hometown of Leesburg, Virginia.

Attended The Academies of Loudoun, a STEM-focused high school which he had to test into during middle school. Michael loved math and science, so he studied engineering at the school's Academy of Engineering and Technology. Played his high school golf at nearby Tuscarora High School.

Hoped to continue studying engineering in college, but realized throughout the recruiting process the demands of college golf would conflict with such a rigorous major, so he shifted his focus to economics upon enrolling at Wake Forest University.

Roughly 12 years after retiring and leaving the real estate industry, Michael's mother, Shannon, earned an expert rules certification from the USGA and became a volunteer on the Middle Atlantic Golf Association Rules Committee. Shannon, who scored over a 90 on her rules exam, has served as a rules official for collegiate and amateur tournaments in the region. Michael remembers Shannon studying for her exams by constantly quizzing the family with different rules scenarios.

Hardly ever read for leisure in high school or college, but one of his professors and close friends, Michael Sloan, encouraged Brennan to pick up books for many years. Brennan and Sloan grew close through their shared love of golf and Sloan’s Greek mythology course. In 2025, Brennan created a Goodreads account to track his reading history and identify what he wants to read next. Two of Brennan’s favorite books – “Island of the World” and “The Lighthouse” – were written by Michael O’Brien, and he hopes to read all of O’Brien’s books.