A psychological phenomenon whereby a participant in a poetry slam has an unrealistic opinion of their abilities based upon an enthusiastic response to their work. But in reality, this is because the only people who attend poetry slams are other aspiring poets who will soon be taking the stage and expect a similar response from the rest of the audience. There are variations of this in music and art.
Sharon thinks that she's a really good poet, but it's only because of the poetry slam effect. She's never made any money or performed before an audience of non-poets.