Only once — when an overcrowded night ferry backed into Gate E7 at Athens’ Port of Piraeus — did my emotions consume me. My breath grew fast and shallow. I squinted through my tears and stammered, “There are so many of them. There are just so many.” There were more than 2,000 refugees on that ferry alone, 35 percent of them children. As a volunteer with the nonprofit Carry the Future, my job was to approach arriving families with babies and toddlers and offer them free baby carriers to ease their journey along the Balkan Route to Western Europe. The families I met were primarily Syrians, Iraqis and Afghans bound for Germany — as long as the borders stayed open. Over the course of their journey, they would cover 1,000 miles on buses, trains and foot. A structured backpack-style carrier or a cozy infant pouch would make an enormous difference to those toting children along with garbage bags and duffels of their belongings. There are just so many. “One baby at a time. That’s all …