The reason people find it so hard to be happy is that they always see the past better than it was, the present worse than it is, and the future less resolved than it will be.

The saying attributes unhappiness less to external circumstances than to a systematic distortion in how people evaluate time. It points to nostalgia that idealizes the past, a pessimistic bias that magnifies present flaws, and anxiety that imagines the future as more uncertain or bleak than it is likely to be. Read this way, “happiness” becomes partly a matter of perception: correcting these temporal illusions—remembering the past more honestly, appraising the present more fairly, and granting the future its capacity to clarify and improve—can loosen the grip of regret and worry. The aphorism aligns with modern ideas about cognitive bias and reframing, even if phrased as a moral-psychological observation.