“Double Scotch, single-malt.” I tried my best to get the words out confidently, hoping to channel Patrick Dempsey’s character, Dr. McDreamy, on “Grey’s Anatomy.” If a three-ounce pour of single-malt Scotch whisky was good enough for a suave television neurosurgeon, then it was good enough for me, a squeaky 19-year-old with his big brother’s ID at a Manhattan dive bar.