After the advent of talkies.

When whalers went to Chile in the first half of the 9th century, they discovered an interesting local popular way of eating popcorn: corn was placed at high temperatures so that the grain was subjected to strong internal pressure, and the core of the starchy raw material exploded as it hit the hard husk outward. This is popcorn.

They thought the little thing was cute and brought it back to New England. Soon, popcorn became popular, and popcorn has become almost a household snack.

The earliest movies were silent, and going to the movies was something that only the upper class could enjoy. Since the movies had no sound, the audience was required to be somewhat literate, and at the same time, worried that the popcorn would stain the carpet, and didn't want the well-mannered patrons to be disturbed by the sounds that came out of the eating of the popcorn. Thus, in the early days, no one ate popcorn at the movies.

Movies entered the sound era, and those who weren't very well educated were able to come and watch. The 1930s in particular gave the movie industry and popcorn a great opportunity to work together. People flocked to movie theaters in order to find a cheap place to spend their time.

The "luxury" of popcorn was within the reach of most people, as long as they had 5 to 10 cents in their purse. What's more, the cost of corn was so low that a 10-cent bag of popcorn kernels lasted a long time.

With more and more audiences watching movies and eating popcorn, theater owners found a business opportunity and began to sell popcorn directly, and with the gradual spread of movie theater culture to other countries, the habit of "eating popcorn at the movies" was also packaged and exported.

Developed to later, people think of the cinema can naturally think of popcorn, watching a movie to eat popcorn has become a ritual event: human beings have this 'habit, once adapted to a particular food associated with a certain type of environment, it will be eaten without stopping. Thus, when watching a movie, people go for popcorn without thinking twice.