You worry about death, not having enough time to achieve your ambitions, the end of your ego. All of which cuts you off from the present like a dark screen. If you bring the mind from miles away to the activity of the moment, if you abate the clatter in your head to focus on the physical reality surrounding your body, and the sensations from within it, you'll gradually experience a surprising sense of well-being. Indeed, tuning in to the NOW is one gateway to perceiving eternity. By experiencing a moment for itself, you stop time.
Time is defined as the interval between two events.
When you are in the NOW there is no interval, only the event alone. The concept of the NOW has great validity when dealing with emotions and the senses. NOW is a point at which you are in touch with the ongoing process. Past and future take their bearings continuously from the present and must be related to it. Without reference to the present they become meaningless.