Forcing people who work for you to give you and others presents is unethical. Appeal to your colleague's better instincts as an educator and discourage this practice immediately. As you are a colleague and not a subordinate, you are in a position to be able to appeal to this person's sense of equity.
My former life as a lawyer required accounting for time in six-minute increments, sometimes confronting the fact that I'd derailed and taken way too long to research something that turned out to be the wrong question. Something similar happened here when I looked up and realized I'd lost 30 minutes scouring wedding related message boards to figure out how one would obtain a suit in his exact size without paying for it.
It's a very easy date to miss altogether in the shadow of December and New Year's celebrations. Growing up, I often received combo holiday and birthday presents. I was taught to thank relatives and friends and not complain that it wasn't fair. Nowadays, an e-card can be scheduled for auto-delivery to someone's inbox months in advance, so it's not even necessary to remember someone's birthday.
