I had no idea at the the time, but i committed a crime that could have landed me in jail for 20 years when i first arrived in Thailand back in 2004. It was just in the bottom of my backpack and I was totally not hiding it so much as I was not at all aware that I was not supposed to have it.
I didn't get caught either and I suppose that this is very very lucky for me because they could have "taken me to the cleaners" over this if they wanted to.
That's it. The highest point of my criminality ever in my life. I acciddentally snuck a poker-chip set and 2 decks of cards into a country that has a very strict anti-gambling policy (unless of course it is the national lottery... that's fine.)
I really had no idea that it was illegal to bring this in but seriously, I was very lucky. They could have put me in jail for a decade or stolen loads of money from me if they had noticed it in my pack.
Point of the story is - don't bring poker sets to Thailand and if you do, never pay more than 19.99 for them because it is a value compared to a completely made up price of $35.