According to the Abrahamic theistic traditions, life is considered a straight line. No turning back or restarts are possible. However, one can always change its direction at any given time through meditation and introspection. On the other hand, in certain eastern religions, life works in a circle. One is supposed to born again and again based on his or her experiences and deeds in previous lives. But the aim is always to break free from its circle and go beyond that. Still no restart from zero and control over destiny is possible.
In scientific realm, Time Travel seems an exciting possibility but it may be decades if not centuries away and the time travelers of future are not willing to disclose its secrets yet. Once it is invented or discovered, human race will have to tackle different time paradoxes and its other manifestations.
... On the other hand, reading or writing a revitalizing piece of prose, composing or listening to some enchanting melody, helping someone without the need to be recognized or rewarded, unraveling or understanding some riveting philosophical problem, falling in love without trying to triumph over and to be content even if it remains unrequited, making a new discovery or solving a long standing mystery, ... in all such endeavors we human experience feeling of transcendence and going beyond ourselves. It is like the feeling of being born again or to be fully alive.
... and there are only ten millions ways to achieve that kind of feeling.