Came back from Taiwan.

Usually, I take a taxi between an airport and Taipei city.
For the first time, I took a bus in Taiwan to go to an airport.

I didn’t know how to pay the money, and other people who had taken the bus didn’t seem to pay the money when they get off.

I thought the bus is free.
Got off the bus, asked a driver to take my luggage, and the driver said ‘pay the money’.

I have learned to have to pay the money before getting on a bus from the next time.