Concluding our treatment of Friedrich Wilhelm Joseph Schelling’s System of Transcendental Idealism (1800), Parts 1 and 2. Start with part one.
This preview (and the full episode) delves further into what exactly the "self" is in Schelling's foundational act of self-consciousness. It can't be your personality, or the thing that makes all of your various experiences uniquely yours, because that would require comparison of experiences over time, whereas this is a single, momentary experience (presumably).
We've said that the self in question is actually the act of self-consciousness, so it's a process, not actually a thing, or rather a process that makes itself into a thing. It's the one point in which object and representation, subject and object, the one doing the intuiting and the object being intuited, become one and the same thing. The self is a becoming: becoming an object to oneself. It is its own concept, meaning that the description is the thing we're describing. It is a thought, and it needs to be re-thought constantly in order to exist at all. Moreover, this is not just a thought that occurs to us, but something we can freely think, and this freedom therefore becomes foundational to our existence as human beings.
This freedom, however, is a matter of spontaneity, not conscious choice. We all do this as human beings, and through it, we posit limits to ourselves by putting objects in front of us and thereby become finite and enter into the flow of time. And we know about this primordial act because we're constantly reinforcing it and can imitate it at any time by just stopping to contemplate. Yes, this is pretty weird, but you can fill out the picture by thinking of Schelling as giving another formulation of Fichte's theology.