This is about 2 weeks after gaining my S1 rating at ZID working SDF_GND:
Me: UALXXX, Taxi to Rwy 17L via D.
Pilot: Ground, I didn't know runways had letters.
At this point, I'm utterly confused. After a moment of silence, I realize what he means. Taxiway D is a long taxiway.
Me: UALXXX, are you talking about the Taxiway?
Pilot: What taxiway? I'm talking about this long, skinny runway. How does UPS have a hub here?
After that, he disconnects.
Welcome to Vatsim.