I will speak from my experience. When I was younger, I considered myself very smart, and I was pretty unhappy. As I grew, I met people much smarter than me; I stopped seeing myself as "the smart" one, and now I am pretty happy. It's not that I became happier because I became less smart; I became happier when I stopped thinking my value was based on my intelligence, so I stopped trying to be recognized by my intellect…
I got labeled "smart but lazy" at a pretty young age (high test scores, didn't do any homework), and I let that label stick with me for far too long. I took some pride in how I could get the top score in a class without studying, and didn't realize that studying itself was a useful skill. I let this whole mindset drag me down through undergrad (especially once I hit the point where I really ought to have studied), an…
Now I am still called smart, and due to the sheer effect of having to get rid of the label, also called hard working, and I'm happy or at least quite content.