You know the feeling. You just had the best tacos of your life, the bill hits the table, and the vacation vibe comes to a screeching halt. Suddenly you're doing frantic mental math, trying to remember ...

Add Yahoo as a preferred source to see more of our stories on Google. In Mexico City, life is a contact sport. (PJ Rountree / For The Times) This is the real-talk portion of your guide to Mexico City.