Living in DC, it's not uncommon to hear several different dialects on a given city block. I placed out of Spanish when I got to college and for a while never really considered getting back in to it. When my family traveled to South America this past winter, I was amazed at how much I understood. When the gate workers in the Cusco airport told us we'd have to check our carry-on luggage, I was able to relay the message perfectly to my family. The problem, however, was that I really couldn't talk back (due in small part to my dad's use of strong slang). Even though I understood every word about why our bags were too big to carry on, I was frustrated that I could only reply in the most elementary sentences and only in the present tense.
After that experience, I became much more aware of just how monolingual I am. More than one person has told me that getting around in Copenhagen won't be too hard because "basically everyone speaks English." As convenient as that is, I feel a new sense of obligation to learn their native language too. Odds are I won't be anywhere near fluent after 4 months but I owe it to myself to try. When I return to Georgetown in the spring, I plan on starting Spanish again. If the rest of the world can speak English, it's the least I can do to master a second (or third, after Danish) language as well.