Of the present state, whatever it be, we feel and are forced to confess the misery; yet when the same state is again at a distance, imagination paints it as desirable. But the time will surely come when desire will no longer be our torment and no man shall be wretched but by his own fault.
 Samuel Johnson, The History of Rasselas, Prince of Abissinia (1759). copy citation

Context

“One who appeared more affected with the narrative than the rest thought it likely that the hermit would in a few years go back to his retreat, and perhaps, if shame did not restrain or death intercept him, return once more from his retreat into the world. “ For the hope of happiness, ” said he, “ is so strongly impressed that the longest experience is not able to efface it. Of the present state, whatever it be, we feel and are forced to confess the misery; yet when the same state is again at a distance, imagination paints it as desirable. But the time will surely come when desire will no longer be our torment and no man shall be wretched but by his own fault. “ This, ” said a philosopher who had heard him with tokens of great impatience, “ is the present condition of a wise man. The time is already come when none are wretched but by their own fault. Nothing is more idle than to inquire after happiness which Nature has kindly placed within our reach.” source