From the movie ‘Inception’ by Christopher Nolan:

 

Cobb:

What’s the most resilient parasite?

A bacteria?

A virus?

An intestinal worm?

 

An idea.

Resilient, highly contagious.

 

Once an idea’s taken hold in the brain it’s almost impossible to eradicate.

A person can cover it up, ignore it- but it stays there.

 

Saito:

But surely-to forget…?

 

Cobb:

Information, yes.
But an idea?

Fully formed, understood?

That sticks…

(taps forehead)

In there, somewhere..