In an interview in 2009, Tokyo-based musician Jim O'Rourke said that Japan is the only place he feels happy. According to the article in The New York Times, "Every time he returned to the United States, his mood sank."
I found myself relating to this sentiment. At age 16 I was in counseling, and at 18 I was diagnosed with obsessive compulsive disorder and depression. Just months before I moved to Japan, I was afraid to touch raw meat and couldn't sleep at night for fear the freezer door was open (thus causing food poisoning and killing all of my flatmates).
Yes, that was how I ruminated. I used to wish I could turn my brain off somehow without sleeping or drinking. Although that isn't possible, living in Japan has at least dialed those thoughts down.