"The transition that's taken place, I view as a rather natural one," he said. "Most people don't get a chance to start over again at seventy years old. ... Janus gave me the opportunity."
He added that "nothing's changed. I'm still obsessively competitive."
Gross's former Pimco Total Return Fund posted its 19th straight month of outflows in November, totaling $9.5 billion, but withdrawals were down dramatically since Gross' sudden exit.
Dan Ivascyn, who replaced Gross, said that net cash outflows from various funds have tapered off significantly, and performance has improved since Gross' departure in late September.
Speaking on Monday, Gross pointed to a time further back in history when fund performance was strong.
"All the way out I had been outperforming the market and Pimco had been outperforming the market," he said. "So it was a little unfair."
In a letter to clients earlier this month, Gross said central banks are trying to solve a debt crisis by piling on more debt, creating a "point of low return" for investors.