Physics has known this for over a century, but it has not reached you yet: time does not flow. There is no river of time carrying you from past to future. Einstein demonstrated in 1905 that time is relative — it passes at different rates depending on velocity and gravity. An astronaut on the International Space Station ages slightly slower than you do on the surface. A clock near a black hole nearly stops. These are not theoretical predictions — they are measured, verified, operational facts that GPS satellites must account for to function. Time is not a background against which events play out. Time is a dimension — as real and as flexible as space. The past still exists. The future already exists. What you experience as the flow of time is a feature of consciousness, not of physics.
The block universe model in physics describes all of spacetime as a single, unchanging four-dimensional structure. Your birth and your death exist simultaneously in this structure — like two locations on a map. You are not moving through time. You are experiencing different cross-sections of an already-complete structure, and the experience of movement is generated by consciousness, by memory, by the brain's construction of a narrative. The mystics said the same thing. The eternal now. The timeless present. The Buddhists call it the dharma of impermanence — but impermanence is only how it looks from inside time. From outside time, everything is permanent — because everything already is.
If time is not what you think it is, then urgency is a construction. Regret is a story about a part of the block universe you can no longer access with your physical senses. Anxiety is a story about a part you cannot access yet. And the present moment — which every contemplative tradition insists is the only thing that is real — is the only cross-section of spacetime you are actually experiencing. The mystics were not being poetic when they said 'be here now.' They were giving you the most practical advice possible: the present moment is the only point at which you can act, choose, or change. The past and future are real — but they are not here. You are always here. And here is the only place anything happens.