Jesus christ I hate when that happens. Mind your own fucking business, I'll smile when I want to

Also, next time someone bothers you with 'I just want to be friends', tell him you already have friends and don't want new ones. Works for me.
Isn't it just the most ignorant, annoying thing ever? "Smile it might never happen", what a thing to say to a complete stranger. Its lucky we have gun control over here or I would shoot people in the face for saying it to me.