With three days left to go in my trip, I was walking around Havana flat broke. I had been spending my convertibles, the secondary currency used by tourists, like Monopoly money. I figured when my cash supply got low, I'd simply slow down my spending. With funds dwindling, I realized I had miscalculated the cost of my lodging, and forgotten about the exit fee at the airport. Cuba is not a place where one can access American banks or use credit cards, so if you run out of cash you cannot get anything. You can't even get off the island. I had been staying in a casa particular, where specific families...