If you claim to study psychology or show an interest in it you would know by now that the "random" smiles you see on the bus or where ever are nothing more then nervousness and the basic trait of disarming a potentially harmful situation. That is the core of a polite smile. They are most likely not smiling at you at all but it is an automatic response to help difuse a situation where they don't have control. Humans do it subconsciously.
Your thinking that the smiles all mean interest is just not normal and honestly I find it a little scary.
I have never, ever said that. Your saying that now ( after seemingly being capable of meaningful discourse earlier) leads me to conclude that you either have not read or failed to understand virtually anything I , or others, have said.
Again, how would you know if every smile is simply a polite or nervous smile? In fact, you yourself said you had coffee with a perfect stranger who accosted you on the street and wanted to give it time to decide if you were attracted to him.
In fact, the whole point is that whilst many of these are clearly mundane, and everyday smiles - some completely fake and probably sarcastic even- some, a small percentage , are often more - and these are ones being discussed and explored in a supposedly positive and adult environment. Indeed, if it were not so then people would not meet and have relationships. People are people-watchers and look, smile, frown for a multitude of reasons... if you have not given or been given admiring or suggestive glances in everyday life then I am truly sorry.
