There are two types of challenges. One that requires to make a decision in a split of a second, another - requires you not to act upon impulse and keep continuing whatever you are doing. Jumping with a parachute or bungee jumping are of the first kind, running (especially long distance) - is from the second kind. While the second kind of challenges usually require some physical preparation, the challenge itself in both cases is mental - to suppress your inner voice of fear, pain, weakness and any excuses. While the first kind gives you more adrenaline rush and excitement, completing the second kind is as fulfilling as completing the first ones. I believe there are a lot more challenges in our life than we choose to acknowledge that - any kind of long activity can be seen as a challenge - anything we do long term is challenging to keep doing it until we see the meaning and reap the fruits of that activity - like learning a language or new hobby, maintaining the friendship or relationship. Especially when we are faced with difficulties - it's so much easier to quit than to continue. But that inner voice telling us to do so might not always be right - it just wants to do easy and fun things without planning too much for the future. But if you already started doing something, it means you already invested your precious time in it - if you quit, you are discarding that time you invested.
