Some people live as though they are already dead. There are people moving around us who are consumed by their past, terrified of their future, and stuck in their anger and jealousy. They are not alive; they are just walking corpses.
The past is gone, the future is not yet here, and if we do not go back to ourselves in the present moment, we cannot be in touch with life.
To dwell in the here and now does not mean you never think about the past or responsibly plan for the future. The idea is simply not to allow yourself to get lost in regrets about the past or worries about the future. If you are firmly grounded in the present moment, the past can be an object of inquiry, the object of your mindfulness and concentration. You can attain many insights by looking into the past. But you are still grounded in the present moment.
Life can be found only in the present moment. The past is gone, the future is not yet here, and if we do not go back to ourselves in the present moment, we cannot be in touch with life.