Imagine if you had a large amount of knowledge, a tremendous amount that would rival any senior technical lead in the field of your choice. You don't know everything but you know you have more knowledge about your field then most the people in the room.
The problem? You have no "experience". Whatever history you had of how you gained your knowledge is gone. Your past is unknown to this new group of people and nothing you say about it makes any sense to them. The only thing that makes sense to them is the knowledge you have of your field.
The obvious answer is to start from the very bottom and spend years fighting your way back up from your pigeonholed existence. But, what other options are there? You know a lot but you have nothing to show for it.