You saying you had no problems is the same as people riding Scooters without a helmut and ignoring the rules . Its easy, no problem until some officer decides to stop and deal you . With immigration of course its a bit more serious if you dont obey the rules and the officer decides to stop you entering Thailand . Its a Holding Cell and deportation back to your home country at your expense , or if you are lucky to a neighbouring country . Not worth the risk imo .