Psychological time-travelers

Few things condition human existence as powerfully or pervasively as the experience of time. Metaphysically, we live in the present, but psychologically we are time-travelers who visit past (memory) and future (imagination, expectation). 

A happy childhood makes it more likely that you will have a happy life. On the other hand, if things go downhill after childhood, then a happy childhood can exacerbate a sense of loss. You mentally compare your happy childhood (if you had one) with your current situation.

Conversely, some people never overcome an unhappy childhood. That dogs them throughout life. 

Some people are very nostalgic about the past. They lament or resent how the passage of time robs them of the things they cherish. Forcing them to say good-bye. 

Some people cling to the past, not because they cling to this life, but because, as long as they're alive, the past was better. Their best years are behind them. incrementally, they've been losing the things that make life enjoyable or undoable. Helplessly they watch it slip away right before their eyes. 

At first they resent having to put those things behind them. And they cling to the past because memories are all they have left. But there can come a tipping-point where, having lost everything they most care about, they now wish to put everything remaining behind them. Get it over with. If they can let go of life, they are eager to let go of the past. 

Although the past colors the present, I think the future colors the present more forcefully. If you had to choose between an unhappy past and a happy future, or an unhappy future but a happy past, the future takes precedence over the past. For the past is behind us. We won't have to experience that again.  

If the future is dark, that casts a backward shadow which darkens the present–but if the future is bright, that scatters the shadows which otherwise darken the present. Whether or not we have something to look forward to conditions our sense of the present. Our view of the present is inseparable from our view of the future. Hope or foreboding? Dread or deliverance? 

As we pass through the lifecycle, we undergo chronic psychological adjustments. Our view of time changes because time changes our circumstances. How we view past, present, and future shifts with the shifting phases of life.