Keira Knightley disclosed that she was initially incredulous about the potential for success of the original Pirates of the Caribbean movie and that she could not envisage how a film could be based on an amusement park ride. Upon seeing the movie at its premiere, she was gratified to discover that she had actually enjoyed it.

disclose - (verb) to reveal

incredulous - (adjective) not willing to believe; skeptical

envisage - (verb) to form a mental image of something

gratify - (verb) to please