I didn't relaize how bad off I I really am

I spent last week with the Boy Scouts at a High Adventure camp called Entrada in Moab. Thursday Morning we did a 5 hour 14 mile mountain bike ride on a trail called "Metal Masher". About half way through, I was wishing I was done. I pushed the bike more than riding. This was a major reality check for me and I want to some day do that ride without pushing the bike up the hills. We also did some hiking in Arches National Park. I had a guy 10 years older than me kicking my but on all the trails. In the past I would get depressed about being unhealthy. This time it is a challenge and instead I want to make myself better.