@Marcin ***********
I'm a tax resident of my home country even if I don't stay physically there. Each country has different rules. I've heard that in some European countries, even the nationals lose their residency status if they don't live there for over xxx days a year. In my country (not European), I'll be always a tax resident IF I earn money from there (such a salary, own business, etc.). I work for a local company and get paid a salary every month, and I also own a small company there. So even if I've been here for two years, I'm still a tax resident in my home country. Actually, I just filled and paid last year income tax a few days ago.
To make it clear, it's not me who chooses whether I'm a tax resident there or not, it's the national tax authority. And they say I still am.
(PS: no income from within Thailand, either)