Could you pass a drug test?

Do you have drug tests in your job or elsewhere in your life?
I have them regularly (or irregularly) in my job (I am a nurse) and I pass them.
I don't want to go into too much details, but they are supervised/monitored and there is not much room for privacy, if any at all.
But I have gotten used to the procedure. Even if in the beginning it was quite annoying.