The First Amendment protects a great deal of speech and almost none of the things people assume it protects. This article explains what it actually does — restrain the government, and only the government — and how the protection varies enormously depending on where you are standing. It walks through the forum framework that decides most protest cases, the difference between a content-based rule and a time-place-and-manner rule, and why permit schemes are constitutional even though prior restraints generally are not. It covers the narrow categories of unprotected speech, why incitement almost never applies to angry rhetoric, and what a true threat now requires. Later parts address arrests at protests, retaliatory arrest claims, the practical reality of qualified immunity, filming police, and what happens when the venue is a shopping mall, a university, or a social media platform. Examples run throughout, including a worked scenario tracing a single march from permit application to federal lawsuit.