The Noetic Ether Hypothesis

A question struck me today:
When we forget a thought, only to remember it later, where does it actually go?
Does it slip into some hidden corner of the mind; some inaccessible room we can’t access - until it decides to surface again?

Or perhaps it's even more complex than that.
What if thoughts aren’t just private sparks inside our heads, but something more fluid; like drifting bubbles in the air, available for anyone to seize, Then as suddenly as you catch it, it escapes.

It sounds mystical, I know, yet we’ve all had moments that make us wonder.
A thought comes to mind yet you decide to keep it silent; then the person beside you suddenly voices the exact same idea, as If reading your mind.
Or your inner voice hums a tune silently, and someone else in the room begins singing that very song.

Where do thoughts go when they leave us?
And are they ever truly ours to begin with?