I try to learn a word a day if I can. I'm not much younger than you and I am indeed retaining it. And whatever I learn I try to use it that day and the next so it becomes ingrained. After a while it just becomes natural. My vocabulary isn't that big and I've been here a number of years. I recommend you try some courses but make sure they go not too fast, make it fun. If that teacher doesn't work out for you then switch. Also how you learn might be different. I like pictures or funny situations that helps my memory work. But really just make sure you allocate time to it each day and practice it. Use it at the 711 or the local market and you can get going on it. You are doing the most important thing right and that is deciding to learn it! So don't give up, it's a fun language. Don't let the script characters get in your way try to hear and repeat the sounds...
Thanks for sharing - yes the BOI team is excellent - I had a similar Smart Visa from the same team that also didn't require 90 day reporting but different requirements. Truly if you can work with the BOI team things go much smoother.
I've had no problems in the "other visa group" we both know which one you are referring to, I know it's hard for some, but you ask the question with some thought keep it focused and you get very precise answers back. And very promptly. What some people don't understand is it's precise and allows that group's questions to become a useful searchable database also. without some wingnut adding other irrelevant questions or the threads full of novices trying to answer. it works.