Not terribly brilliant or original, but:

  1. The reason you shouldn’t argue with TSA folks (e.g., about how many carry-ons you can bring on-board a flight into the U.S. from Canada) is not that you won’t win (although you won’t) but that division of labor gives them an advantage. They’re experts. (PS. The answer, apparently, is one.)
  2. The smaller the airport, the tighter the security. Only place I have actually been physically patted down: Sioux Falls (FSD) in South Dakota. Only place I have been told that I couldn’t take a small bit of toothpaste on-board because the original size of the tube (not the small amount left, but the original size) was more than two ounces: Sun Valley in Idaho (SUN).

PS. I’m not sure this counts, but yesterday I flew out of Calgary (YYC) and had the following experience: my jacket went through the scanner; they picked it out and sent it through the scanner again; they did a physical search of my jacket and found a (less than 2oz) container of hand sanitizer; they told me I needed to put it in a plastic bag; they put it in a plastic bag; and then they sent me on my way!