Living a good—and/or successful, blissful, healthy, contented, happy—life depends on something very simple, but also as rare as it is delicate: your attention.
That which you put your attention on has a direct impact on your quality of life. Focus on loss: you become the loss. Focus on feeling like shit: you become… Focus on the negatives, you become negative. Focus on Facebook notifications, you become, for all practical purposes, a notification.
Your subjective experience—how you think about yourself, others, and the world; how happy you are, how driven you are, how focused you are; and so on—is fundamentally dependant upon attention.
Where you direct most of your intention determines a large part of your default mode of being—the way you think, feel, sense, behave, communicate, love. You may dip out of such states as negativity, loss, of feeling like shit, or a notification, but because they are your default state you slip back into them as quick as you slipped out.
The beauty of this truth is that it works the other way; your default state can also be one of optimism, confidence, beauty, positivity, strength, endurance, even bliss—if, that is, you direct in in the right place(s) most of the time.