Thailand's sex industry is indeed massive, but the vast majority of it caters to Thais; the bits that target Westerners -- a few dozen gogo bars in a country of 67 million -- just happen to have a much higher profile. Essentially all the women working in it are there of their own free will, if almost always because of economic hardship. (Typical scenario: Poor rural girl gets pregnant, boy disappears/dies in traffic accident. Girl can't support child and herself with farm labor or factory work, so she leaves the kid with grandparents and goes off to Pattaya.)

And oh: the "me so horny" line comes from Full Metal Jacket, a Vietnam war movie.