I know it's not Tuesday

I'm a (subconsciously) selectively shy person. Sometimes I exude confidence as I go into an interview. Sometimes this is too much. Just yesterday I approached an unsuspecting college kid sipping coffee and asked about what he thought of his beverage. He gave me the most terrified "deer in the headlights" look of utter fear. He said he had no idea. After I apologized and left him be, he quickly gathered his things and ran out of the coffee house. But other times, I am consumed by fear myself. I freeze and don't even approach the person. I have no idea what causes this phenomenon of spontaneous shyness. The only thing that keeps me going through these interviews is the possibility of it working out and getting a profound and life altering quote.