Cannabis occupies a position no other product does: lawful and regulated under most state laws, and a Schedule I controlled substance under federal law that has not changed. This article explains what that contradiction actually means for consumers, patients, workers, business owners, and people with old convictions. It covers the Controlled Substances Act framework, why state legalization does not preempt it, and the specific federal consequences that survive state law — firearms disqualification, immigration exposure, federal employment and housing rules, and the tax provision that makes state-legal businesses pay tax on gross profit. Separate parts address employment testing and accommodation, banking and payments, landlord and tenant issues, child custody, and the record relief that many states now offer. It also explains hemp and the products derived from it, which occupy a different and rapidly shifting position. Examples run throughout. The article is written for consumers, patients, operators, and lawyers.