The Tongariro Crossing is suppose to be New Zealand's best one-day trek. The hardest part is a steep climb up The Devil's Staircase, which puts you in the alpine pass between two volcanoes, one of them being Mt. Doom from Lord of the Rings.
At the time, I was anxious about climbing to an altitude of 1,900 meters, as I had never been so high on foot before. One of the things I love about traveling is how fast you can gain experiences and confidence. It can be as if you squeeze more of life into a shorter amount of time. A few months later, I reached 4,330 meters on a trek in northern India! And a few months beyond that, I was already thinking about trying a 6,000-meter peak in Bolivia (but that will have to wait for another year).