That isn't necessarily true. If you are a reliable patient, they should have no problem with that. Over the past year I was battling cancer, and my doctors knew I was on methadone, and also that I was quite knowledgeable about pharmacology and whatnot. They literally asked me what was the most effective for pain, becuase of my high tolerance they knew percocet wasn't going to do anything. So I told them 8mg dilaudid 3 times a day was the only thing that actually helps with the pain on top of my methadone. They just said Ok, and that was that.
I have a feeling that half of these people that go into the doctors office with the hopes and intentions of getting something prescribed, either make it sound like they are stupid, and a junkie, and probably look like a junky too. I wasn't even trying to scam them, my pain needs were legitimate and they knew that. And despite my past they knew I was knowledgeable and trusted my opinion because I didn't come off as a stupid dirty unintelligent junky.