I do this all the time. Quite often, I see people I recognise and just pretend I haven't seen them. When they're gone, I wonder why I even did that. It's such a gut response! I always think I won't do that again but surely enough I do. Even when it's someone I like. Sometimes I manage a hello but find it a bit painful, like, will I need to stop? How close do they need to get before I say anything? Do I just stare at them as they're walking towards me? Anyone else like this? I swear I'm not horrible.