Going after a dream has a price. It may mean abandoning our habits, it may make us go through hardships, or it may lead us to disappointment, et cetera. But however costly it may be, it is never as high as the price paid by people who didn't live. Because one day they will look back and hear their own heart say: 'I wasted my life.'
If I extend an empty hand and in retrieving it and finding it still empty, I feel disappointment, that is foolishness; yet if I extend a hand which is full and yet find no one to receive it, then that is hopelessness.
Peace comes from within. Do not seek it without. It can be argued that peace and happiness comes from the subjective internalised perspective of realizing things could be worse and being grateful they aren't. The alternative view that peace and happiness comes from the objective external perspective of having more and better things than at present, while important for growth, can be a never-ending source of jealousy, dissatisfaction and disappointment. A balance of the two, where people are grateful for what they have while striving for more seems the best blended perspective.
It has sustained me in moments of success and in moments of disappointment. Without it, I'd be a different person. And without it, I doubt I'd be here today.