The key to time travel is to realize you are likely *already* in your past. And you have, right now, the opportunity totally reshape the future.
Consider it from a probabilistic standpoint: those of us aware of time travel will likely put in great effort to revisit key moments in the past where we could have made a difference, where we could have made a better future. We likely go back again and again, effecting perhaps only small changes each time.
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