This reminder alone solves the angst of most worry and depression. Once you come to realize that you can't undo the past and you don't control the future, you'll start to enjoy each present moment of your life. You'll come to appreciate the reality of WHAT truly IS!
There's nothing wrong with recalling the joys of your past from precious moments which have been created for the "present memory," however, you should not dwell on regrets of the past, which may inevitably lead down a dark road of depression. You should also not overwhelm your mind with trying to control what has not yet come to pass...This does not mean be reckless in not planning for your future, however, you have no control over the actual outcome and it doesn't yet exist.
LIVE for today....for THIS moment.....for What's REAL - NOW is all there ever is!