1. When internal motivation fails -- e.g. when it's approaching single digit temperatures -- it's extremely helpful to have external motivation.
2. When running in a sub-arctic frozen tundra, make sure to bundle up appropriately, and THAT INCLUDES CHEEKS.
3. When my calves don't tighten up, it turns out that my endurance is actually pretty good, and I can run longer than I thought I could.
4. Hills aren't so bad once you get used to them, and
5. It's a lot easier to run when you are distracted by conversation, even if it's through a tinny speakerphone, and even if your mouth is too cold to properly speak English.