When you live in the present, you lose track of Time. You no longer gauge how long you may have to live.
It is scary to let go of Time. To let go of awareness of Death. When we are aware of Death, it feels distant, like it is always on the horizon.
To be truly present is to remove the distance between our experience and oblivion. It is the recognition that Now is the only moment that exists, and that the future is just a mirage.
You are only alive for the present moment, but in each moment lies an Eternity.