The past, the present and the future

I was teaching a lesson yesterday about the ancient Israelites - they had trouble moving forward as they continued to look back to Egypt instead of looking toward the promised land.  Part of the discussion was on looking towards the future - having dreams or goals and looking towards them - which I thought interesting as I have also heard and recently posted about living in the now.  I have also heard many statements about remembering the past and learning from it.  So which is best to live in, the past, the present or the future.  Of course the answer is easy right - all 3 a balance of all 3.  I started thinking about each one and thought I would discuss it a little
The past: how can living in the past be harmful.  When we wish for things the way they used to be we may miss out on opportunities now, or not see the blessings that we have.  If we think about or regret choices we have made we may be riddled with guilt and unable to move forward.  A healthy dose of forgiveness is important to have towards others as well as toward ourselves.
How can remembering the past be beneficial.  If we do not learn from the past we are doomed to repeat it.  We should learn from the choices others have made, from the small to the large - from wars, from our ancestors, but learn from them to move forward.  So if we are looking at the past to improve the present and future I think that would be healthy - otherwise we should focus on moving forward.

The present: What if we only live in the present.  Well obviously that would lead to some selfishness as we would live for the moment and the fun of what is currently ongoing.  Also as this is limited site we probably wouldn't always make the best choices, but if we are stuck in regrets or so busy looking for the next good thing/the next project to complete, we may miss out on the joys coming from the moment.  So when we are making choices we should take into account the past choices we have made, how our current choice fits into our overall pathway of life and effect the future, but once we have made a choice we should fully enjoy ourselves or fully live in the moment so as not to miss something by only looking forward to the next moment or thinking about the past.

I often miss what is going on at the moment by thinking about something I may need to do the next day or looking forward to something but when the time comes not immersing myself int he moment.  I also sometimes "assume" that each event will be similar to one in the past - I can ruin a good vacation, thinking well last time something bad happened so it might again.  This also assumes a negative purpose towards others actions if we see them as if the person has already injured us, when they haven't done anything yet.

The future: While we should plan for the future if we are always waiting for the next activity/project etc.  we will not enjoy the one we are currently on.  If we fail to plan or make goal we will end up somewhere on the road to life, but most likely in a completely different location than the one we wish to have been.

In what ways do you find a balance in the past/present/future? or In what ways have you found yourself caught up in one that has effected you positively or negatively?