It's the actual living in the past and attempting to live in the future type thoughts that keep us from riding the waves of time, or living and thinking at the true flow of life. The peace or turmoil in our life lies not in what's going on around us, but in what's going on inside of us - our thought life. It is a person's attitude alone that determines his or her perceptions. Whether I make a mistake or I am a victim of someone else's mistake, I do not have to continuously think and talk about it and live in the wrong that I did or that was done to me. By missing this never changing flow of time, and by keeping the mind and thoughts outside of the movement of that flow, one is constantly living backward and forward, but never in the peace of the flowing present.
Time is relevant.
Einstein proved that thoroughly. As difficult as it may be for some to grasp, the flow of time for one person may not be the same as the flow of time for another person. Marching to the beat of a different drum may best describe this phenomemon, where not only is the drum different, the beat heard also varies greatly. And all human beings certainly aren't riding the same wave of time. One of the wonderful aspects of time's flow is its readiness in letting one back on a wave.