The obstacle shows up as a conviction that one has no particular ability. The person compares themselves with recognised names, arrives at the obvious conclusion, and never starts.
This is the most galling of the points, because it is almost always wrong: behind it stands a real creative ability that the person has no idea about, precisely because of it.
What it blocks is the ability to create and to be seen.
What to do: make something and show it, without judging it in advance. Judging is the work of those who will see it, not yours; yours is to make sure there is something to see.
A sign that it is receding: what you make goes out into the world instead of staying in a drawer.