A CEO explains how the answer to an unusual interview question helps determine who should get hired (TREX)

Most job candidates go into interviews expecting to discuss their previous jobs, academic work, and hobbies.

But James Cline, CEO of the outdoor decks-maker Trex Company, prefers to reach even further into the past by asking, "what's your oldest memory?"

"I want to understand their background, their roots, where they came from, what it was like growing up," he told Business Insider.

If an interviewee played softball, for example, Cline would want to know whether they were the kind of player that threw the ball as hard as possible to try and hurt the other person. And in business, like a sports field, that's not necessarily a bad thing.

"How open and how closed they are with those answers gives you an insight into those people," Cline said. "When people open up and are free-flowing, I feel a lot more comfortable in the hiring decision than if everything they say is guarded."

If they're unwilling to share, "I know I'm missing something — I just don't know what it is — so that makes my antenna go up about three feet."

His own oldest memory, from when he was "about three or four years old" is amusing. Cline, 66, recalled napping in his grandparents' house and waking up to discover he'd been left behind when the other kids went out. He was so upset that he threw his shoe at his grandpa out of anger, who, thankfully, found it hilarious.

"I learned at an early age that if I do something wrong, fess up," Cline said. "The anticipation of what's going to come — because you know what's going to come — is worse than [saying] 'I did this, I deserve a spanking, let's have it.'"

These kinds of responses about early childhood reveal how a person's personality developed, and what it could be like to work with them, Cline said. And as a bonus, they make interviews more fun.

"You've got one hour to try and figure out whether you like this person or not," Cline said. "Life is too short to have somebody working with you that you don't like."