That the past is ahead, in front of us, is a conception of time that helps us retain our memories and to be aware of its presents. What is behind us [the future] cannot be seen and is liable to be forgotten readily. What is ahead of us [the past] cannot be forgotten so readily or ignored, for it is in front of our minds' eyes, always reminding us of its presence. The past is alive in us, so in more than a metaphorical sense the dead are alive - we are our history.