Sleepless in the canyon, Ralston is reminded of what other occasion in his life and why?

On one of Ralston's ultra-hiking trips, he hikes for two days straight. In this time, he falls asleep for 20-30 seconds at a time as his partner approaches. It is a hike that feels like it repeats itself over and over. Ralston compares it to the movie Groundhog Day where the main character replays the same day over and over again every morning. The situation in the canyon is comparable with his sleepless nights.