I've always enjoyed challenges from when I used to mountain bike hard every day at the state parks around my area to running upwards of 20 miles per week. I joined a gym a few years back and started going daily and working out with weights and then spinning (stationary cycling in a darkened room with music and an instructor).
The workouts were always hard and I determined to push and punish myself to really feel and earn my workouts. I used to work out so much, I thought why not become a personal trainer and motivate others but didn't do anything about it. I then thought, why not become a spinning instructor and motivate others but didn't do anything about it. I've been thinking a long time now about running my first marathon but haven't taken the steps to keep training myself.
I guess the point is it doesn't matter too much if you don't accomplish the things you had hoped for as long as you continue down a path that makes you happy and healthy.