Readers reply: what are thoughts? Where do they come from – and where do they go?

The long-running series in which readers answer other readers' questions on subjects ranging from trivial flights of fancy to profound scientific and philosophical concepts

What are thoughts? Where do they come from, and where do they go when they disappear? Are they filed" somewhere, a bit like memories, where we can find them again, or once a thought has gone is that it?
Sue Christian, Oswestry

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