Some people can be fast metabolizers of specific drugs.
How long have you been taking temazepam? You might have simply built up an enormous tolerance. And the two things can go together - if you take a drug for a long period your body can become more efficient at metabolizing it and you can build significant tolerance, so that the drug is being eliminated more quickly and it doesn't have the same effect due to changes that have occurred to the receptors and other complementary neurotransmitters.
