Concerning mood, I have been reading Edith Jacobson's book, Depression: Comparative Studies of Normal, Pathological, and Psychotic States. It is easy to overdo thoughts about mood when traveling, I think. Perhaps because it is also easy to overdo mood. Jacobson makes a distinction between mood and affective state on the basis of the "generalized" nature of mood--its capacity to recode all feelings in the pattern of the mood, regardless of whether or not these feelings are related to the same particular object.
picture: "Beach," Berlin