I can still hear Freud’s quote: “Where does a thought go when it is forgotten?”
Where does it go?
That sends me straight into Alice’s Wonderland where the Red Queen has the ability to remember the future.
If time is linear then the past loses relevance and the future is at stake because as we over-prepare for those eventualities we actually sacrifice our present. 
Perhaps this is why people go to church.
Perhaps religion gives them those ten minutes within which they can get lost in meditation and allow their dreams to take flight in the safety of a future. Perhaps this is why we create art; because in those hours, if we can find the concentration and get into the flow we forget who we are, all our complaints, all or needs, are gone.
Where does that forgotten thought end up?
I might suggest many things, but in the end, all I could ever hope to convey, would, at least to some extent, be tied to episodic memories and I’m not so sure there would be any real accuracy in that, especially given that I am no longer now who I was then.
“Echoing Meghan O’Rourke’s poetic assertion that ‘the people we most love [become] ingrained in our synapses, in the pathways where memories are created,’  Goldstein writes:
A person whom one has loved seems altogether too significant a thing to simply vanish altogether from the world. A person whom one loves is a world, just as one knows oneself to be a world. How can worlds like these simply cease altogether?” 
They don’t cease, but with every passing second we change.
Semantic memory grants us a backdrop for our future dreams and episodic memory allows us to attempt to predict an imagined outcome.
Without this we would have no plans, no goals, no dreams. We would be as good as dead. There would be nothing left to fight for and our terminal degrees would be buried deep within our past.
Knowledge is the gateway to our deepest humanity.
Written by Boky Hackel