capture (one's) imagination
To hold one's interest or spark one's creativity. I know it sounds strange, but his talk on the importance of obtuse angles really captured my imagination. That movie captured his imagination so much that it inspired him to become a screenwriter.
capture someone's imagination
Fig. to intrigue someone; to interest someone in a lasting way; to stimulate someone's imagination. The story of the young wizard has captured the imagination of the world's children.