I get like this when I'm meeting people from the internet who I never met in person. I feel like I'm not going to recognize and will be like really awkward.
Ah! That's a good one! Like meeting someone you contacted on Craigslist to buy some stuff from or something. I sold a bunch of Japanese books online a few months ago and it was interesting to see all the different people that contacted me and met me to pick them up from me.