All three actually.They're all connected anyway.
It's important that we don't forget our past because it's partly why we are who we are right now thanks to the good and bad experiences alike.
I don't allow myself to get absorbed within my past though,especially because there are a lot of things that I already made my peace with.
The present part is important because it's about right now,and if we take the right choices now it pays off in the future.Every second counts.
The future part is also important because it's all we can be...the possibilities are endless.
Down side of thinking about the future

I could obsess and get a teeny tiny bit off course.We're good though