Three years ago I left my job as a distribution center manager. We required drug tests for every applicant and I asked them about specific drug use during each interview, letting them know they would be tested for alcohol, weed, meth, prescription drugs, etc.
Time after time (about 50%) I was told, “No problem, I don’t do drugs” and the tests would come back positive.
The funniest was a man in his late-20’s, who, when confronted about his failed drug test, admitted that his friend who provided the sample promised that the urine was clean! It was among the most drug-addled samples I had seen.
Can't trust anybody these days.