First, Nooruddin "Rudy" Karsan, 58, sold Kenexa, the human resources software company he co-founded, to IBM in 2012 for $1.3 billion, taking home far more than the $50 million originally reported.

Then, he sold his Ferrari, and several cars - and he didn't stop there.

"One of the things I did, post-sale, in the last 18 months is I took all material things out of my life," he said.

"I had a Ferrari," Karsan said. "I got rid of that. We moved from a 9,000-square-

foot home to a 2,000-square-foot condo right here in the city. I own no second homes anymore. I literally have seven pairs of pants."

Wow, I'm impressed. I find it hard to toss my holiday cards. Why did you do it?

It just makes me feel so happy and right. I'm not married to anything. I'm not collecting anything material. I'm only married to my experiences.

I love life now. I don't know how to express it.

How do you express it?

I don't want you to make it sound like I'm a do-gooder.

If I've got an hour to spare, I'll walk [down] the lines in [a local utility office]. I'll just spend cash and pay utility bills. I tell the security guard I'm paying his utility bill and I tell the teller the same thing. I never give my name. That's one example.

I love this country so much.

After you sold Kenexa, you stayed on with IBM for a bit. Next came Karlani, your investment company.

I'm a rookie investor, OK? Being a rookie, you make rookie mistakes.

I decided to do this probably six months or so before I left IBM. When you've had a big exit, you think you're God's gift to the business world. You are infallible.

The first investment I made was a [software] company in the Middle East. It was a bust. Within 18 months, it dropped seven digits.

Seven, as in closer to $1 million or closer to $9?

Right in the middle.

Was that all your money, or was it Karlani's?

It was all my money.

How can you screw up that badly? Because you believe you are infallible. You've got a huge ego. You've got the world telling you how smart you are. You've got people like you writing about it. You start believing all this [stuff] about yourself.

So when I started realizing those mistakes, I said, "OK, I've got to set the parameters of how I am going to do this so that I stop making these stupid mistakes."

I was surprised you sold Kenexa, although maybe I shouldn't have been.

It was extremely difficult. I actually physically cried myself to sleep a few nights after having made the decision, then going through the closing. It was a sense of loneliness, emptiness, lack of purpose. I went through absolute misery, soul-searching, and I've come out on the other side.

I'm absolutely loving life, because it's allowing me to play in areas where I have a lot of natural curiosity.

You interview executives and entrepreneurs. What do you ask them?

On my first meeting, I want to understand what [their] perceptions of death are.

What I find very interesting is people who have thought about death will respond differently from people who haven't.

But what does it tell you?

How introspective they are.

Their language and description will tell me whether they're an introspective person. So that's the trait I'm trying to pull out. It's a very difficult subject to be introspective about when you're in your 20s and 30s. So you have to be at the extreme edge. You have to be an outlier to even have an opinion.

I'm looking for outliers. I'm not looking for average. I'm looking for home runs. I'm looking for changing the world.

In addition to investment, Karlani offers management consulting to the companies it invests in. How does that work?

We can help them troubleshoot a problem. So basically, we're working for them.

Our charge for this is $250,000, either in cash or equity. You get five [executives] at your disposal, except you don't pay until at the end of the year [and only] if you believe we're worth it. At the end of the year, you can say, "Thanks, I'm not going to pay you."

You get moved to the passive [investment] category. We're still your friends. We've got money invested in you. Or, you can pay us less. I'll ask "What are the two or three things we failed on so that we don't make the same mistakes again this year?"

Interview questions and answers have been edited for space.