Two breathless hikers at the high point of the rim of Diamond Head crater

Science has recently confirmed what I think of as the full disk theory of memory. (NY Times January 21, 2013.) As we age we add tons of new experiences, but we can’t break the connections to old ones and thus have more trouble forming new long-term memories. In other words, our brains get overstuffed, but don’t empty out in the same way our stomachs do when we overeat.

As my husband and I panted and sweated our way to the top of Diamond Head crater on Oahu a few weeks ago, all the past hikes I’ve suffered through came to me in a rush, starting with my first trip up Mount Si in the Snoqualmie Pass area. This was a hike spearheaded by one of the dads of a girl in my Girl Scout troop. His idea of a father-daughter bonding experience. He and the other dads soon learned that taking a bunch of out-of-shape eight year old girls on a crawl up a steep four-mile trail on a cold, wet day was not a good idea. The dads couldn’t stand our tears for long and turned us around before we made it to the top.

Then there was the trip my husband and I made to Chichen Itza, the Mayan ruins on the Yucatan Peninsula. Here we climbed inside a temple located within the pyramid, El Castillo, to see a turquoise and jade jaguar. We were not alone on our hike.  The line of fellow climbers stretched from outside the pyramid to the top of a set of narrow inner stairs, no hand rails. Climbers brought in moisture by virtue of breathing, moisture that created wet, slippery steps. Going up was not difficult, but on the return, looking down at all the people below me, I realized that one person skidding on the slick steps would create a chain reaction that would cause us all to tumble. We laughed at the thought that if this site and others like it in Mexico were in the U.S., they would have a tough time getting liability insurance.

The Great Wall of China, which we accessed at the “most visited section” called Badaling, was another breath-sucking hike.  High risers, narrow treads and a steep slope caused me to buy a certificate — stamped when I reached a certain high point — testifying to my completing this rigorous climb.

Honolulu from Diamond Head

But back to the crater of Diamond Head, also known as Le’ahi.  Encountering stairs mid-way up reminded us of the earlier hikes and a dark narrow tunnel brought back memories of being inside the pyramid at Chichen Itza. The Oahu park system brochure says that the Diamond Head hike, “0.8 mile from trailhead to the summit is steep and strenuous, gaining 560 feet as it ascends from the crater floor.”  A woman in the park gatehouse told me that on a moderately busy day, three thousand people make the climb.  Watching hordes of people of all ages and physical condition reach the top, we were determined to make it. In eighty-plus degree weather, we worked up a sweat, but compared to the other hikes I’ve mentioned, this one was relatively easy. Definitely safer and not strenuous enough to push out the vivid memories of the old ones.

We spotted lots of birds along the path and a mongoose in the picnic area at the entrance to the park. It’s a descendent of a mongoose imported by sugarcane growers in hopes they would control rats in the cane fields. The experiment failed. Mongooses snoozed at night when the rats were active.  No rats were killed but the mongoose population grew and now is a danger to many species of birds.  Now that’s a story I just might remember.