So I'm at the grocery store after work today. I spot a woman looking at the deli meats. She turns back towards me and I get a clearer look at her face. It turns out it was an old classmate of mine. I've been out of school almost 25 years now and have not been to any reunions. I sat next to this girl in several classes because our last names are close alphabetically. So we often chatted but were never close. Obviously she didn't recognize me. Would you have stopped and talked to her if you were in my situation? It goes without saying too that I would end up outing myself to her.
In a related question, I had a close friend in high school who I kept in touch with for a while after but fell out of touch with him 6 or 7 years ago. There is still a fair chance that I could run into him at a local 5-k since both of us are still avid runners (we were on the track and cross country teams together). How would you handle such a situation if it were to occur?