Two years after the start of Beatlemania, the band were open to exploring new themes in their music through a combination of their tiring of playing to audiences full of screaming fans, their commercial power, a shared curiosity gained through literature and experimentation with hallucinogenic drugs, and their interest in the potential of the recording studio. John Lennon was encouraged to address wider-ranging issues than before in his songwriting through Dylan's example. A further impetus was a discussion he had with BBC journalist Kenneth Allsop about whether, as in Lennon's 1965 book "A Spaniard in the Works", his lyrics were conceived as merely "another form of nonsense rhyming". Author Mark Prendergast describes "Rubber Soul" as "the first Beatles record which was noticeably drug-influenced". In Lennon's description, it was "the pot album".