Besides the "happy birthday" from cast members, only one special thing has happened while wearing a pin. But, it was simple and made my day (and yes, I'm a 31 year-old guy).
A few weeks ago, I was walking through the gift shop after riding Space Mountain, and a male cast member (maybe 50?) said, "Happy Birthday! Come over here."
I said, "Thank you," and walked over to him and another cast member (female, 25-ish).
We talked about how he had seen me walk through the gift shop after riding Space Mountain earlier in the morning, and he was curious if the CM assigning seats was smart enough to put me in seats 2, 3, 5, or 6 because of my height (I didn't mind since he was also tall... there's an unspoken club of tall people, I suppose). We talked a little bit more, and he said that he had someone who wanted to talk to me. He handed me a phone, and I listened to Goofy sing "Happy Birthday" to me.
It cracked me up, and made me laugh. It's probably the simplest, but best, birthday present I received this year.