I greeted someone from my building (not native to this country) yesterday with the phrase "howdy howdy." He looked at me quizzically and asked me what that meant. I paused, and it occurred to me that moment how absurd that was—I had essentially said "how do you do how do you do," and even a single "how do you do" is already archaic enough. After the pause I just said, "er... hello hello." He replied with a slightly confused "Uh, hi."