What did the Double Ninth Festival activities make me understand? 300-word essay

Today is the Double Ninth Festival. In the morning, our school conducted a special broadcast on the Double Ninth Festival. The broadcast introduced the customs, origins, etc. of the Double Ninth Festival. It was very interesting.

The day of study passed quickly. After school, I saw Teacher Shen on the stairs and thought, today is a holiday, so I have to bless the teacher politely. So, I quickly said: "Teacher Shen, happy holidays!" I thought that Teacher Shen would definitely say "thank you".

Who knows, Teacher Shen looked at me strangely. Why didn't she say thank you like usual? I'm a little confused. At this moment, Teacher Shen said with a smile: "I'm not old, why are you telling me happy holidays?" What's going on? I feel very puzzled.

When I got home, I quickly told my grandma what happened and asked her what happened. Grandma laughed and said: "Double Ninth Festival is also the Old People's Day. Is Teacher Shen old?"

Hearing this, I suddenly realized. Originally, I thought that we should always say "Happy" to each other when we encounter festivals! But I forgot that today is a special holiday, and it was all my fault that I didn't listen carefully to the radio, which made a big joke of "showing off one's skills to others".