Yes; that's what a Schedule I drug is. Possession is a federal offense, and the intent does not matter at all. Violation of federal laws can and will get your clearance revoked, even if it's legal in the state where the offense was committed.
Absolutely no law is enforced 100% of the time on everyone equally. There's always a political/social calculation being made and balanced. It's childlike naivety to believe that perfect enforcement ever could (or should) be the case. Akin to believing Santa knows if you've been bad or good so be good for goodness sake.