Serving as President Donald Trump’s chief of staff may be the pinnacle of retired Marine Gen. John Kelly’s distinguished career, but Kelly nevertheless says his favorite job was as a Marine noncommissioned officer.

“The best job I ever had was as a sergeant in the Marine Corps,” the Washington Post quoted him as saying in August, shortly after assuming his White House position.

“And after one week on this job, I believe the best job I ever had is as a sergeant in the Marine Corps,” Kelly said, according to the Post. 

Born in Boston, Kelly enlisted in the Marine Corps in 1970 and rose to the rank of sergeant. He left active duty in 1972 to attend college and then was commissioned as a second lieutenant in 1976 after graduating from the University of Massachusetts.

Kelly retired in January 2016 after spending more than 40 years in the Marine Corps. Both of his sons joined the Marine Corps. In November 2010, 1st Lt. Robert Kelly was killed in Afghanistan while serving with the 5th Marine Regiment. Kelly was notified of his son’s death by Marine Gen. Joseph Dunford, who is now the chairman of the Joint Chiefs of Staff.

During his final four-star assignment as head of U.S. Southern Command, Kelly clashed with then President Obama about the White House’s plan at the time to release detainees being held at Guantanamo Bay, Cuba.

“They’re detainees, not prisoners,” Kelly told Military Times back in a January 2016 interview. “Every one has real, no-kidding intelligence on them that brought them there. They were doing something negative, something bad, something violent, and they were taken from the battlefield. There are a lot of people that will dispute that, but I have dossiers on all of them, built and maintained by the intelligence community, both military and civilian. There are no innocent men down there.”