SAW A FRIEND IN CENTRAL

It's really hard to describe the feelings when you meet someone you haven't seen for few years. Would you just say hello straight away? Would you look at him until he is aware of you? Or would you pretend you don't know this person? In normal circumstances I would give him a friendly smile and make sure he has recognised me. I didn't plan to go to Central tonight, I was looking for Pedder Street and I just wanted to ask someoe. Then I saw this friend unexpectedly. Obviously he was busy with talking to his friend and I didn't want to bother him. I think may be I was just scared of talking to him :P It would be so embarrassed if he couldn't recognise me :P