Going to a big gatherings like Ropecon is great opportunity to meet people I wouldn't normally meet. There are a lot of like-minded people I have come across in some other similar contexts. Maybe we have played in the same game once or twice in the last. Maybe we met in another event like this. Or maybe we have only met on the same event in previous years.
These acquaintances wary in depth. There are those we have actually worked together to make a game and then there are those we have maybe talked briefly once before. This can lead to situations where I might be talking with somebody from the former group and then somebody joins the conversation briefly. Afterwards, when they leave we are left wondering "who was that? Did you know them?" and neither have any idea. I'm pretty sure I have also been that person others don't remember more than once.