An anonymously sourced report from Semafor about Demis Hassabis’s departure from his Google DeepMind CEO role, and his transition to a new role as chief scientist at parent company Alphabet, seems eager to clarify that he left of his own volition, and that he had apparently wanted out for a while.

Alphabet announced the move as part of a wider leadership shakeup on Wednesday.

Sources Semafor calls “two people familiar with [Hassabis’s] thinkingâ apparently said Hassabis, a Nobel Prize recipient, was increasingly unsatisfied with his tech executive job, and longed to be a scientist again.

Semafor writes that:

“His passions lie in using AI to solve scientific puzzles, like curing diseases and discovering new materials, and in ensuring that AI doesnât accidentally cause catastrophic harm to humanity.”

To that end, the anonymous people said, this move has been in the works for at least a year, with Hassabis slowly ramping down his duties related to consumer AI at Google and the company’s Gemini AI projects, and Google’s chief AI architect, Koray Kavukcuoglu, slowly taking them on.Â

Like many of its comparably sized tech juggernauts, Google is spending money like crazy lately. While it’s decidedly not one of those companies that typically fuels its day-to-day operations with investor money and promises of big profits to come, in the second quarter of this year, Google’s self-reported free cash flow turned negative for the first time since it went public in 2004.

“As a business we are in an incredibly strong position,” Hassabis wrote in a memo on Wednesday. No other company, he wrote, “has the full stack.” Google DeepMind, he said, “has all the ingredients to lead from here, and I firmly believe we will.”

Hassabis will still have a role as chair of Google DeepMind, and will continue to be in charge of Alphabet’s AI drug-discovery division Isomorphic Labs. That division is deeply intertwined with AlphaFold, the AI protein-folding program that is, essentially, the work that won Hassabis his Nobel Prize.