There's a scene in the Oscar-winning movie where Woodie Allen sees a happy couple on the street and asks them why they're so happy. Their response is classic:

The scene works because, as with most jokes, there's some truth behind it. According to many studies, intelligence (of the intellectualizing variety) and happiness don't always go together. As an article in The Atlantic recently put it:

"Being better educated, richer, or more accomplished doesn't do much to predict whether someone will be happy. In fact, it might mean someone is less likely to be satisfied with life."

In the recently-published book If You're So Smart, Why Aren't You Happy?, Professor Raj Raghunathan of the University of Texas at Austin explains that smart people make themselves unhappy by measuring themselves against external yardsticks that become ever more difficult to achieve.

As Raghunathan explained in The Atlantic article:

"If you get a huge raise this month, you might be happy for a month, two months, maybe six months. But after that, you're going to get used to it and you're going to want another big bump. And you'll want to keep getting those in order to sustain your happiness levels. In most people you can see that that's not a very sustainable source of happiness."

Smart people tend to be very goal-oriented, which makes them peculiarly vulnerable to tying their happiness to "winning" or achieving those goals. They are correspondingly vulnerable to feeling depressed when things don't go well.

The problem is more acute for entrepreneurs who, as I've pointed out previously, are especially prone to depression. When you're depressed, even a big win won't make you happy. Meanwhile, a big loss or ongoing problems can send you into a downward spiral.

In other words, smart people often make themselves miserable by being too goal-oriented. By contrast, people who aren't so goal oriented are more likely to feel satisfied with themselves and their lives.

While no smart person wants to be "shallow and empty," there's a lot to be said for not obsessing about external achievements and instead being in the moment, especially when you're doing something that you truly enjoy.

So, while it's fun to scoff at the vapid Annie Hall couple, there's real wisdom in the idea of emptying your mind. In fact, that emptiness of mind (and freedom from external goals) is a key element of Taoism, one of the world's great religions: