However, recently I risked a quick look. Bizarrely, the face looking back at me reminded me of someone, apart from myself.
A moment's thought led back to my last year at primary school, and Bill McCann. While my generation grew up in the flower power days of the 1960s, for Bill and his generation adulthood was reached to the accompaniment of buzzing tracer bullets in the cockpit of a Spitfire. Perhaps that's why he was such a gentle man - in every sense of the word.
Bald with greying hair and an ex-RAF moustache, I can see now how much he enjoyed teaching and how amused he was by the earnestness of his young charges. Always there was a twinkle in his eye and a chuckle in his voice; the brown tweed suit, the pipe and the brown brogues completed the picture.
It's not surprising that I can recall such detail after more than 40 years. As the only child of a widow, such a father figure was an obvious requirement for me. A far lesser man than Bill may well have claimed my attention, but I was lucky to get him - the epitome of all a teacher would want to be.
Most of the memories come in freeze frames: calling the register from his desk; explaining an arithmetic problem patiently; with a colleague on the rugby pitch, suit trousers tucked in his socks, wearing rugby boots, trying to kick conversions from the half-way line - a sign to us youngsters that adults could still have fun.
But the biggest memory is no snapshot, rather a film loop with perfect sound and senses. It's Thursday afternoons, wood smoke smell drifting in from the playground, the last half-hour of the day, and Bill reading to us from The Wind in the Willows. Even now, I can't think of the book without hearing his gentle tones bringing the words to life. Who can tell how much of my love of literature and teaching came from those perfect moments in a silent and attentive classroom?
Of course, I never told him, and now it's far too late. But, looking at the image in the mirror, I do reflect that there's no one else I'd rather resemble.
Sean McPartlin is depute head of St Margaret's Academy, Livingston