Street Approval

The other night, I was leaving 7-11 with some beer and a couple of guys in an SUV pulled up beside me at the light and gave me the thumbs up. I returned it. I'm friendly. But I didn't know what it meant. Did they see me buying Guinness and think that was awesome of me? Are they applauding our mutual disregard for our national dependence on Mid-East petroleum resources? Is it my tank top again? Los Angeles friendships are easily made, but why can't they be infused with more meaning?