Being growth/challenge oriented is good for you as a human being. We grow and stay strong in response to stressors, mental and physical. But the hard thing about pursuing ambitions (or acting against discontent) is appreciating where you are even as you attempt to change where you are.
If you can't find a way to appreciate life as it is now, you're not likely to be happy when you arrive at wherever your life is headed.
Upon arrival, there always seems to be the call of a new destination or ambition or challenge which does a great job of distracting you from the good that is all around and within you right now.