Rule #1 of city living:
Always, ALWAYS carry cash. No corner market will accept cards for purchases under $5 and all you will want is some tasty-looking 50-cent bananas. You will go home empty handed.
(Also, one day you WILL discover you need to do an emergency load of laundry, have no quarters, and no dollar bills to exchange for quarters. You will end up wearing that tacky shirt you liked in eighth grade that you meant to take on the last Goodwill donation trip. You will be ridiculed by everyone you love.)