A great career but......
The element of autonomy in the teaching world was what appealed to me about teaching compared to other (employee style) careers. The freedom to shape the class how you want it, to plan with students for future events, group discussions, mock exams and much more made TEFL an interesting and fun challenge.
However, in Thailand, especially in the full time government school field, this is often taken from one - or narrowed down to the mantra that one must 'follow the book' but taken literally as in, page by page. After that, students are examined on the contents of a book, rather than on their level of English.
This makes teaching a low level skill that can be picked up by anyone with a bit of confidence and native English. It is a great pity, especially for the students on the receiving end, and can reduce the number of skilled teachers who want to stay here.
Elisha