At 22, Daniel Ek reached his $10 million goal and felt empty

At 22, Daniel Ek finally got to be the cool guy. He had money, and he spent nights in clubs where women paid him attention in a way they never had when he was a teenage computer geek.

Ek, the founder of the music service Spotify, had grown up with little in the projects in Sweden, meaning public housing estates for lower income families. He felt like an outsider as a boy, outside every social group, and he says he still feels that way, even among other entrepreneurs.

At 15, after reading the personal finance book Rich Dad Poor Dad, he had set himself a magic number. If he ever had $10 million, he could retire. He figured that if he worked very hard, he might get there by 40.

Instead, he reached that wealth at 22, after selling his first company. At first, he was, in his word, content. He had fun for a while, using money to buy status and attention.

Then the fun turned hollow. He realized the women in the clubs were not with him because of him, but because of his status and money. He no longer had his company, he did not have to work for money, and he did not know what to do next.

So he walked away and did almost nothing for more than a year, reflecting on life and what he wanted. Looking back on that time in the interview, he agrees with the description that he was consuming, not producing, and making nobody else's life better.

It was, he says, probably the most depressed he has ever been. He had known from a very young age that he wanted to build things.

The lesson stuck. Ek came to believe that happiness comes later, when you look back on a hard problem you solved for someone else, and not in the moment you spend the reward.