Book: Long giant
The mind can be your best friend, may amuse a man when, say, there is nothing to read and nothing to do. But when he gets the new data is too long, it turns against man, against himself, starts to tear and torment myself and maybe devours itself in unimaginable act of amocanebis.
However, we do not know how to measure the time pure consciousness... moreover, we simply can not imagine, what is a pure mind without a body.