Oddly I found it both relaxing and nervy at the same time. Fog can be beautiful and I have some Welsh and Norse ancestors that it sings to. On that level I find it soothing.
Meanwhile, back in the real world, I also have to deal with the reduced visibility. Both my ability to see cars (and judge distances) and that of the drivers who might not see me. So some degree of caution applies on mornings like those.