Is "home theater" a difficult term?

Last month I gave a speech on "home theater". My audience had little knowledge on this subject. So I tried to make it very simple without using technical jargon. The title of the speech itself was "home theaters" and I used the term at least a dozen times during the speech.

After the speech, several people talked to me appreciating my speech. Here are few samples.

"You made the dry topic of home entertainment systems very interesting."

"I wish I had  a movie room like yours."

"Your speech on your stereo system was nice."

"I am glad that my husband did not hear your speech. Otherwise he will build a media room like yours this weekend"

I was stunned. Entertainment system? stereo system? movie room? media room?.  I never used these terms in my speech - not even once.

This was not my first experience. Whenever I talk to people about my hobby of home theaters, many of them later refer to it as "media room" or "entertainment system".

Is "home theater" such a difficult term to remember? 

I don't understand.