Such a difficult lesson, and one that must be practiced diligently throughout the entirety of one's life; the difference between contentment and achievement!
You can immediately tell when you meet someone which category they fall into. They either emit a genuine confidence to pursue their goals for self-exploration, or they emit an ego-based confidence rooted in personal achievement!
I'm not telling you to not set goals and achieve them. I'm asking you to be aware of where your sense of self-worth comes from!
If you pursue things in the name of personal achievement, you will never be fulfilled--and I say this from experience.
True fulfillment is calm, and motivated only by creative freedom--a desire to further understand yourself and your craft. Personal achievement is fleeting. And so, in order to both "achieve" externally and find a sense of fulfillment and happiness, you have to keep a close eye on which is which.
Otherwise, do you know what's going to happen?
You're going to climb that big mountain in front of you, grind your face off to reach the top, and before you've even taken in one single deep breath and enjoyed the view, you'll notice the next mountain and think, "Oh, actually I haven't achieved anything--I must need to climb that mountain, too!"
- Nicolas Cole (modified by Amr Badran)