Rolling your own JWT authentication is basically the security equivalent of performing brain surgery on yourself because you watched a YouTube tutorial. Sure, you technically implemented authentication, but you've also probably introduced 47 different attack vectors that a security researcher will gleefully document in a CVE someday. There's a reason why battle-tested libraries like Passport, Auth0, or even Firebase Auth exist. JWT has so many gotchas—algorithm confusion attacks, token expiration handling, refresh token rotation, secure storage, XSS vulnerabilities—that even experienced devs mess it up. But hey, at least you can brag about it at parties while the security team quietly adds your endpoints to their watchlist. Pro tip: If your JWT implementation doesn't make you question your life choices at least three times, you're probably missing something important.