Originally Posted by
FliesWay2Much
I view this as very similar to getting detained at a sobriety checkpoint and being asked "Have you had anything to drink tonight?"
If you answer "no" and they detect alcohol on your breath via their special flashlights, you've just lied to a cop. If you say "yes", you may have just incriminated yourself. So, I've taken the approach to simply decline to answer that question.
It's not the same. The checkpoint officers don't ask, "Have you EVER had anything to drink and driven?"
Even if you answer yes there are no consequences. A visitor admitting past drug use however faces being turned back and banned.