I know people who constantly try to "sell" their free courses.
It is free. You should come.
Is it really free?
The person I know will brag about how many attendances he has, but he will also lose my time.
When I was younger, I wouldn't mind to do random activities. At the moment, I prefer to invest my time, rather than spend it.
Free is the new expensive! Be very careful when someone offered you something for free!