Memory brings forth the past, anticipation, the future. The thing that must be realized is that there is only the present: memory and anticipation are useful tools that bring those times into the present, helping us to grow, learn, and change. Yet there is a danger here: to remember is to inhabit a state that has already past and to anticipate is to inhabit a state that has yet to come. We cannot live our lives in constant remembrance or anticipation because to do so would be to inhabit a time that is not our own. This very notion is entirely contradictory to the nature of human existence, or possibly the nature of existence in general: we have only ever been and can only be creatures of the present.
We cannot live in the past or future for it goes against the very nature of living: it is only possible to live in the present. Life spent caught in the past or lost in the future is not life at all, but merely a dream from which we need to awake in order to truly live.