SACRAMENTO, Calif. (AP) — Doug Willis, who followed Ronald Reagan from the governor’s office to the presidential campaign trail and covered Jerry Brown’s first stint as governor during a three-decade career writing about California politics for The Associated Press, has died. He was 77.

He died Tuesday night at a hospital in Sacramento from complications following hip surgery, said his wife, Judy. He had been diagnosed with Alzheimer’s about three years ago and had been living in a memory-care home since summer, she said.

Judy Willis said it was especially sad that her husband suffered from dementia because he had such a quick wit, nimble mind and failsafe memory throughout his journalism career and their 22-year marriage.

“Somebody once called him a walking encyclopedia,” she said. “It’s absolutely heartbreaking.”

Indeed, Willis was something of an anomaly in a profession notorious for its aversion to math: He had won a full-ride engineering scholarship to Stanford before getting bored with that major and switching to journalism.

Colleagues recalled him as a congenial but fierce competitor who never forgot a fact or let sources off the hook.

“He didn’t give up. He would get his question answered,” said Rebecca LaVally, a Sacramento State University communications lecturer who was a reporter and manager in the state capital for the competing wire service, United Press International, during the 1970s and 1980s.