Answer: inform listeners about planning for the future
Explanation:
The author’s purpose of this speech is to inform listeners about planning for the future.
The author wasn't telling the listeners how to apply for a new job or about seasonal changes. The author was informing them about the life after high school and what they need to do to plan for the future.
If you're meaning like Greek myths and Victorian myths than it would be like
1. They're stories started by one person
2. They've been around for years now
3. They've probably been changed over time as people tend to change memories and stories each time they tell it
4. They could be a lie started by one person eons ago