I've told this before but I was at a small music festival in France, at a bar, waiting to be served. I got talking to a lady in the queue, she was there for the festival too.
She asked me what I was most looking forward to. There were loads of good acts but I said, despite all that, I was looking forward to seeing a talk by David Keenan, a favourite author of mine.
She said, "I'm his publicist, he's over there, come with me", and I had a drink with him. He kissed me (platonically) and we had a really good talk about his work and related subjects. It was amazing. Casual, not awkward, just chatting. Pure magic. Beyond a dream come true.