Go for the adventure, not to try and change things
The one big thing that I've learnt being in Thailand is that farang teachers won't make a difference to Thai society. So many guys I know, myself included, came to Thailand with the best of intentions and the rosiest of glasses, hoping to "make a difference" or "save those poor kids from their oppressive culture", only to end up frustrated and bitterly disappointed. Thailand doesn't want to nor should it change or modernise simply because a few western, white knights want it to. Word of advice- go for the adventure, go to travel, enjoy and work hard but don't expect to make a difference to Thai society.