This quote from Kay Redfield Jamison's book, Exuberance, made me laugh right out loud. Startled the cat.
"An individual in a positive mood tends to see the forest and the pattern among the trees; an individual who is in neither a positive nor a depressed mood picks out the trees. Someone who is depressed focuses in on the bark (and then notes, as well, where it is peeling)."
Some trees I can identify by the bark in winter when they have no leaves. I'm not joking. (But I am still laughing.)