The experience of free will certainly exists. That is, whatever is happening when a decision is made by a conscious agent, the agent experiences feelings like indecision, fear, or desire feeding into a final decision.
My question is around the phrasing "I have free will" or even "the agent experiences". What, exactly, is the agent? When a person says "I have free will", what is the "I' that they are talking about?
How have different philosophers defined "I"?