Quote from a WSJ piece, The Happiness Myth (h/t, Dr. Bob):
...a lot of us seemed a lot happier, or at least less restless, before the Happiness Movement began bullying us. Myrna Blyth, a longtime editor in chief of Ladies' Home Journal, made this point explicitly in her 2004 book, "Spin Sisters." Ms. Blyth undertook an informal study of the themes in women's magazines as they evolved over recent decades, and concluded that what women have mostly gotten from their magazines is the message that they're never quite happy enough -- never good enough, never fulfilled enough, never far enough along on the path to "having it all."
Read the whole thing. My simple-minded theories are that, if you wonder whether you're happy, go out and try to please somebody else. Or get on your knees and ask the Lord what He wants you to do. Or go shoot some targets or birds: that always works because happiness is a warm gun.