CONCORD, N.H. (AP) — While setting a speed record for New Hampshire hiking, Philip Carcia was sometimes struck with a sort of reverse déjà vu. Halfway through a hike, he'd question whether he had completed an earlier one on his list.

"I'd get fanatical about checking that I had been to peaks," he recalled. "I'd think, 'I can't really remember, was I on Cannon in February? I don't have a vivid memory of Cannon in February.' And I'd start to kind of panic a little bit. As soon as I'd get home, I'd look at my data and see the notes and think, 'Phew, OK, cool, I was there. OK, we're good.'"

Given Carcia's goal, it's no wonder the days blurred together. While more than 10,000 people have climbed all 48 New Hampshire mountains with summits over 4,000 feet (1,219 meters), fewer than 100 hikers have completed "The Grid" — reaching every summit in each of the 12 months. That adds up to 576 climbs and 2,700 miles (4,345 kilometers), and it often takes years, if not decades, to achieve.

On July 7, Carcia became the second hiker ever to cram the Grid into a single year, beating the previous record by five weeks. It was 319 days of extreme highs and lows, in both elevation and emotions.

"This trip was punctuated by so many days that were just sheer glory or sheer madness," he said in a recent interview. "This is a really, long epic project that took me to both ends of the spectrum — both heaven and hell."

Carcia, 35, bookended his quest with the White Mountain Direttissima — a 240-mile (386-kilometer) route connecting all 48 of the peaks. The initial push in late August 2018 took eight days, while the final sprint took six and a half. But it wasn't quite the joyous victory lap he'd envisioned. As he covered about 40 miles (64 kilometers) a day on mangled feet and two hours of sleep, hallucinations popped up along the trail — a cluster of rocks became a car or refrigerator, a tangle of trees an ironing board. As night fell, the images grew darker.

"My brain would identify the textures on the ground, the textures on the rocks, and the roots as faces," he said. "I started to be convinced that these faces, these eyes on the rocks, could kind of see through me and see into my struggle."

But those last punishing days also were rewarding, he said, because they reinforced his core belief in being a pioneer, not a conqueror. It wasn't about dominating the mountains, it was about submitting to them.

"I had climbed all 48 4,000-footers in 11 consecutive months leading up to that last round, I had climbed almost a million feet of vertical, I had thrown down every single day in one of the gnarliest winters on record, and I was still being humbled," he said. "I was still paying dues. I was still walking on those trails not feeling like I should be puffing my chest out, but feeling genuinely small."

Carcia, who grew up in Massachusetts, didn't start hiking until he was 16, though he said he first felt the pull of the White Mountains as a toddler, gazing out a car window during a family vacation. By his 20s, hiking consumed him — he tackled the Appalachian Trail, the Pacific Crest Trail and more. His father's death in 2014 propelled him back to New Hampshire, where he channeled his grief by hiking all 48 mountains in under four weeks.

Once he decided to attempt the single-year Grid, Carcia spent three years preparing. He completed two rounds of the peaks in winter 2016, and climbed Mount Wachusett near his home in Massachusetts 300 times in the six months leading up to last August. He then moved to a small town in New Hampshire and got a job at a hostel, where he squeezed in shifts between hikes.

Adam Mooshian attended a talk Carcia gave at the hostel in December and ran into him several times during his own quest to reach all the summits in one winter. He said Carcia offered unfailing support to other hikers, including the time Mooshian woke up at 3 a.m., terrified about a long traverse ahead.

"I picked up my phone and there was a text from Phil that said, 'Make it happen because no one just happened to make it,'" Mooshian said. "I rolled over and read that text, and thought, 'OK, it's coffee time. Let's do this.'"

Sue Johnston, the first person to complete a single-year Grid, told a reporter after she finished in 2016 that she loved "every day, or almost every day." On her blog, she wrote, "The entire year was a JOY. I never got tired of hiking, it never ever felt like a job, and except for a couple of rainy hikes, I was always excited to spend the day walking in the woods and climbing mountains."

Carcia's experience was different — he said he both loved and loathed every single mountain at some point, and there were days he woke up dreading the task at hand. Still, he is already thinking about his next adventure.

"I still don't think I've quite reached my potential out there," he said. "I see myself going back out there and pushing myself and trying to raise the bar, and committing myself to being a pioneer in these mountains that I really, really care about."