Now you might wonder why a seemingly sane and rational person suddenly began to believe that they were the saviour of all mankind. Perhaps unsurprisingly, the story began on a park bench with a packet of legal highs.
It has become an indelible etching on the national psyche; cannabis and psychosis dovetail like fish and chips. The impact of cannabis on the mind has been well documented in the British press, but it remains an unfortunate muddle as the link is as far from clear as one is led to believe.
The great majority of terrorists aren't found to have any form of mental illness. However, the situation is less clear with so-called 'lone actors', 'self-starters' or pairs who aren't part of any mainstream group.