I remember I had two tourist books for my HS NYC trip, and one recommended never taking the subway ("because its mostly for locals, and hard and confusing" or something like that), and the other basically didn't mention it at all. Filling a Metro card was like discovering a secret power in how much of the city I was able to see in a short timespan.
One of my favorite stories from that trip was getting a call from my father that he got last minute Broadway tickets for us in a couple hours, while I was on the Ellis Island/Statue of Liberty ferry. When he heard where I was on the map he was concerned I might not make it to dinner/the show on time, and I knew I had the timing on my side with the Subway to get there right on time. (And I did.)
