are there certain situations where your stuttering disappears?

are there certain situations where your stuttering disappears? does anyone has that? in my case, the moment I stark working (video rental store) I'm so confident and fluent in my speech, almost nothing literally stops my speaking. But I discovered, when I my brain tells me, "hey you, try not to stutter" there were some situations where I started stuttering. The next days I didn't think about it, and there was no stuttering at all.