Nick Cutter said this quote

The water wasn't the same down here. Water is what runs out of the kitchen taps or a playground drinking fountain. It fills bathubs and pools and yes, of course, the ocean- but at a certain depth, water becomes a barrier from all you remember, all you think you know.You're trapped within it, a plaything of it.Focus erodes. Your thoughts mutate. The pressure.The pressure.The soul can't cope with that. It shouldn't be expected to.Humans weren't built for this. There's a reason nothing lives down here.Or nothing should.