Is this true or is it just a fib (requires of bit of reading)?

So the other day my friends and I went out to get some ice cream after finishing a rigorous game of basketball. Now at the ice cream place that we wen to, the cashier that took our orders was an extremely attractive young lady. And she smiled at me. After that my friend, that's a girl, would not stop nagging at me saying that I should go talk to the cashier because she didn't bother to look up at any one else and smile, except for me, while she was taking the orders. Ultimately I didn't go talk to her because I honestly thought she was just doing her job, being a good employee and serving the customer warmly. But no my friend kept insisting on me going over to talk to the cashier because according to my friend "it's a good sign". So I wanna know, am I right and is my friend full of crap? Or is my friend right and did just ruin a good opportunity?