Here's a thought that I've been playing with for a while. I'm not certain if it's a literary conceit, a gedanken experiment with concepts about human souls and the Big Bang, or sleep deprivation.
So, she said, tell me what you think...
Past and Future are just stage names for Memory and Imagination. Memory and Imagination are the parents of dreams.
Dreaming is, therefore, our only way to travel in, or master time. Or perhaps without memory or imagination we are stuck in time.
Too much Doctor Who, perhaps?