but why no helmet?
mark.
A helmet is much more uncomfortable, more difficult to carry and store than a face mask. The benefits of a face mask are immediate and obvious each time you ride--you don't get so much dust and pollution in your lungs. While a helmet only protects you from a very rare event.
The QR code is your receipt. Keep it incase you have any problems.
Thailand is just following the example of the many, many other countries who use QR codes for the exact same thing. Singapore, Malaysia, Philippines are a few nearby examples.
Not always. I'm a US citizen. The IO still usually asks you what countries you went to while you were away and how long you were out of the country. Answer those wrong and you will be pulled aside and questioned like I was recently. I've had more problems entering my own country than any of the other 100+ countries I've been to.