Some kid in eastern europe watched Kobe Bryant play and got inspired to sign up for a local basketball team and took it seriously - that’s influencing. People in some countries outside of the US that never had Halloween as a holiday now unofficially observe it (due to the holiday’s portrayal in western media and it being almost a staple for a sitcom series to have an episode dedicated to it) - that’s influencing.
But you are right, it isnt the type of an influence you are thinking about, with an evil man twirling his moustache and trying to manipulate people on the other side of the globe to do his bidding via harry potter movies.