Fifty years later, Renee Pantoja hasn't lost the curiosity he had as a 7-year-old.
Pantoja was a second-grader at Pomona Elementary School when it first opened in Costa Mesa for the 1961-62 school year.
He watched crews seal a rectangular copper box in the wall outside the front gate with the promise it would be opened after 50 years.
As the anniversary approached, that capsule weighed on his mind.
"I was just excited to find out what was in the box," he said.
So he contacted the district with the help of some former school staff and showed crews where to exhume the historical container.
"I was just being selfish, quite frankly," he said.
On Wednesday, Pantoja satisfied his curiosity when Pomona staff had him open the capsule and announce to a crowd what he had found.
A crop of current Pomona students gasped in awe as maintenance workers unscrewed a metal plate to reveal a dedication plaque from the 1961-62 school year.
"Behind there, there's a special treasure," Principal Megan Brown said.
In the yard, Pantoja recalled sitting with his fourth-grade class during a lightning storm. They had run outside with a teacher to gauge their distance from the storm by counting off the seconds between lighting strikes and thunder claps.
On that quad, after popping the capsule's lid with a putty knife, Pantoja pulled tangible memories from the box.
Inside were documents: an invitation to the cornerstone laying ceremony at Pomona, original staff and student rosters, and a districtwide report penned by the then superintendent.
Last was an April 26, 1962, edition of the Daily Pilot with headlines blaring the first crash landing on the moon with the Ranger 4 spacecraft and the planned construction of a $2-million recreation center on the west Harbor Boulevard south of Baker Street.
The capsule will make its way to each classroom at Pomona in the next few weeks for students to inspect up close, Brown said.
Janet Steward, a former Pomona administrative assistant who started in 1981 and retired 10 years ago, met Pantoja through Facebook and helped him contact the school. They were curious about the box.
"We just didn't know what to expect," she said.
They did, however, want to make sure the capsule wasn't forgotten at a campus they remembered so well.
"I can't imagine having worked at any other school," she said.