How about this? What if time does not exist? What if time is simply a human construct to help frame important events in the past and the future? Time is a way to explain in a linear manner what has happened or is about to happen. To me, time is merely an observation of motion, whether it be the movement of the sun from horizon to horizon, the movement of the sun dial's shadow across the ground, the pendulum of the clock, the second hand of a watch, or even the vibration of the quarts crystal or movement of electrons through the circuit of a digital watch (if you are fast enough to be able to observe it); time is movement. Even the activity within the brain, synapse-to-synapse, is movement of chemistry and the spark of life. Without movement, there is no life.
What if it's possible that our stumbling block in making other things possible is believing that time is real? What if there IS no past and no future? Just right now... At this time, it can't be proven that we could go "back in time" to stop the priest who rescued 4-y-o Hitler from a river, or go into the future to see what lies ahead for us. What if these science fiction movies about time travel are flawed on the belief that time does exist? Remember, it's just movement in the now that you're watching. It doesn't exist yet, nor does it exist anymore once past. You just happen to remember it, that's all.
If you have a head injury and permanently lose those memories, those events that happened no longer exist unless they're recorded in a very accessible form for other people to see and learn, and/or other people still remember it. They only exist up here, in your head. What is left behind, though are consequences of our actions; the people born as a result of unions, buildings and things left behind as legacies of politics and human organizations, and changes to the landscape as reminders of human impact on the environment.