monomaniac

Each of them had his monomania; and the two monomaniac suited each other perfectly.

Even today tens of thousands of educated men regard him as a monomaniac concerning the abolition of slavery.

Hunted and hated in two worlds, Hradzka dreamed of a monomaniac's glory, stranded in the past with his knowledge of the future.

Sleeping or waking it was the same, wherever he looked those sad eyes met his; there was no escape; he was becoming a monomaniac.

Of course no one not a monomaniac would so entirely ignore your side, would conceive so strange an idea.