Study after study has suggested that life happiness is a U-shaped curve. We report we’re happiest in our teens (I don’t remember it that way!), with a low point in our early 50’s. Then we get happier again in our 60’s and 70’s (that I can definitely attest to). “[It] is a healthy change, but there’s a nasty transition in the middle”
Here’s an excellent example of one man’s discovery of the happiness curve, and how it helped explain his mid-life funk: The Happiness Curve, And Why Your Midlife Isn’t A Crisis.
This composite graph (and great article too) combines seven different happiness surveys, and shows they track a similar path. They seem to predict we’re going to have a midlife crisis, and then come out the other side feeling good.