Most of us know what we're like when we're stretched too thin. The team is short-handed, the calendar is full, and every person who stops by with a question feels like one more thing to get through. I've been that leader more times than I'd like to admit, which is probably why a bartender in Madrid made such an impression on me. He was running a packed wine bar by himself, with people waiting at the door, and he still gave us his full attention like we were the only ones ther