Never Take Your Eyes Off Your Bags
Never ever take your eyes off your bag. Especially in Thailand. That includes putting it in the undercarriage for bags on the large busses. Had $1000 USD stolen from it (my massive mistake putting money in the bag, I know. I was wasted when I did so). They put small children or little people in duffels with all the other bags so once the bus starts moving, they search through all of them and crawl back into their little bags. Still angry about it.
Story credit: Reddit / MidnightLiving