Experience. It is STUPID to do steroids if you are still learning what works for you as far as lifting and diet. I think you should be natural until you reach you plateau.
A lot of people don't even have a proper routine and skimp out on legs but lift chest and arms twice a week. But people will do whatever they want to do, and many of the logs on here show that, pics or no pics.
It absolutely amazes me that you still get guys drinking on cycle, or asking for advice on AAS when they obviously don't even have basic lifting or nutrition down.
It's weird though, seeing new people on here who have amazing results with steroids, but then there are "experienced" guys on here who have done multiple cycles and you can't tell either way.
I honestly think most people put too much stock into supplements and these oral steroids early on, and never really get their training and diet dialed in.