One reason that the author says the loch ness monster is just a figment or our imaginations is because there have been no increased sightings since the invention and prevalence of cellphones and digital cameras. Even with the use of satellite technology, no scientists have ever been able to find anything in the loch. When the BBC tested the imagination theory, they used a fence post and had it rise out of the water in front of tourists. when later asked to draw what they had seen, they all drew the iconic monster head.
One popular theory is that Nessie is a plesiosaur from the last ice age; however, it is impossible for one have survived this long for all of these years, especially with so little food in the lake.