I would have to say it was a little bit of luck because I made a few missteps. However, knowing what I know now, I could have made it 15 minutes quicker if I had not tried go direct from the North terminal to the South terminal via the shuttle bus. If I had gone straight through customs in the North Terminal and straight to the ticket counter, I would have saved 15 minutes. The other key item was that I did not check my bag and that I got a seat as close to the front of the plane as I could.