Well, i have been here for 15 years and my Thai is abysmal. But i have my excuses.
1. A hearing problem. Not the volume, just a very narrow range of pitch. It makes a Tonal language like Thai a struggle. On the phone, even English words are misheard to often.
2. Also maybe slightly dyslexic. Dyslexia was not really recognised when i was young. I can read English OK but writing was always a bit harder. Do not start me on Thai characters!
3. Not for want of trying. I have, at various times, tried to learn French, Spanish, German, Dutch, Swedish, Slovak, Cantonese, Arabic and a couple of West African languages as well as Thai. After a month i hit a wall, know a few words but mainly, they just do not 'stick'.
4. In Thailand, rarely had any problems. in shops and Offices, between my Thai, their English, a phone translation app and my wife, get a result. Thais all learn some English at school, just most do not care about it and never try to learn it properly. Thai casual conversations? For me, forget it.
Am i stupid? No, i have 2 science degrees and can do basic maths in my head (something my wife couldn't understand). Music, languages not easy.