You don't need to "explain" because you don't make the rules. I follow the official rules. But good to see you back-pedalling over your ridiculous statements! 😂
Yes, and the country where the capital gain is realised is the country where the tax is paid. The OP is on a retirement visa. Foreigners are only assessed on remittances sent to Thailand. Anything else which remains in another country is beyond the reach of Thailand. Honestly, some people have no idea