Bill Gross: Here's why I started over at Janus Capital

Exclusive: Bill Gross on starting over at Janus
Exclusive: Bill Gross on starting over at Janus

It's not easy leaving an empire and trying to build another one, but Bill Gross, lead portfolio manager at Janus Capital, said it's something he had to do.

"I'm obsessively competitive, and it's an area that I not only enjoy … but love and thrive in. So, I knew that even at 70 years old, it's better to work than to not work," Gross said in a frank sit-down with CNBC's "Power Lunch." "I've seen examples of people that retire and got bored very quickly, so I said 'I'm good at it; I had a great record in the last year or two or 30 at Pimco, and there's no reason why I can't keep doing it.'"

Bill Gross
Patrick T. Fallon | Bloomberg | Getty Images

Gross left Pimco, the investment management giant he founded and ran for more than four decades, in 2014. He started working at Janus, a much smaller firm, about a week after leaving Pimco, but immediately recognized that it was "very different, and not entirely in positive ways."

"The positive was fewer meetings, fewer exchanges with people that tend to clog up your day. I enjoy trading and watching markets," he said. "I did miss, almost immediately, the investment committee. Pimco has a brilliant investment committee, or had; probably (it's) still pretty functional. I missed the two-hour-a-day interplay, in terms of the committee with eight people jawing at each other back and forth, so there's trade-offs."

This is the first part of a three-part series of exclusive CNBC interviews with Bill Gross.

— CNBC's Brian Sullivan contributed to this report.