On a summer family vacation to the upper peninsula of Michigan several years ago, I went trail running on a gorgeous system of cross-country ski trails, everything was going great until I turned around a corner and was overcome with the feeling, “let’s get out of here fast.”

I don’t know why that happened. There was nobody else around, and I couldn’t hear any sounds that sounded like someone hiding behind some trees or bushes, but I just knew that I wanted to hightail it out of there as quickly as possible…