'Love & Mercy' delves into life of Beach Boys' Brian Wilson

The Beach Boys helped create a feel-good era in music known as the 'California Sound.'

But years after the band hit it big, one of the co-founders, Brian Wilson, began to lose his grip on reality.

Wilson's struggles are portrayed in a film called 'Love & Mercy.'

The movie is a biopic tackling his life, his music, his genius, and his mental illness.

Not one, but two actors portray Wilson -- Paul Dano and John Cusack.

They each spent a week with him to learn his mannerisms and learn the story from the musical icon itself.

"It was kind of like therapy for me. It was therapeutic for me to see how I produced records and how I used to sing," Wilson said.

The film delves deeply into his sickness.

Wilson was misdiagnosed as a paranoid schizophrenic and spent years in treatment.

He says he hopes the film will inspire people

Wilson says he is proud to share his story and felt relieved that his fans can know his truth.

'Love & Mercy' is in theaters now.