You've read the documentation. You're familiar with all the tools at your disposal as well as those of your adversary. You've understood and can actually implement the best practices for anonymity, online and in meatspace. You are more paranoid than Nixon. You might well be an infosec consultant.
You're also a junkie. You get urges. You need the shit and you need it now. You've made plans, made purchases, made allowances, but you still end up looking for that little bit of residue on the surfaces, the pipes, the screens, or, God forbid, the carpet.
So you end up violating every single rule you know. You buy coin and can't wait to transfer it to your favorite DWM. You use a single wallet. You trust Bitcoin Fog to launder your BTC efficiently with as little delay as possible. You end up using TorBrowser as your only tool.
It is natural for a drug user to minimize latency and take some major risks. Just remember that instead of simply getting beat or getting a pass from local cops for coping a personal use amount, you might well end up in the shit for the dope and everything else that you buy: IDs, papers, services.
Don't ditch your local hookup. You just can't plan ahead.
Order a good quantity so it lasts. If it comes late, buy locally but just to get by before the package arrives.