That is a tricky point to answer.
The bulk of the cortex learns by “simple” Hebbian process - relatively slow. The fact that patients like HM are capable of learning skills like mirror writing without any memory of having done so reflects that the episodic memory is what is missing when the EC/HC is compromised.
Due to the distributed and interlocking nature of the representation, the cortex capacity is enormous. To understand this; there are only a small number of letters in an alphabet but due to combination and the rules of grammar they can represent a large number of objects and relationships - the concept is much the same.
The EC/HC has a much faster learning rate but relatively small capacity. Also, this learning rate is modulated by other subcortical structures, notably, the amygdala. The copy held in the EC/HC is like an index key in a database - replay during sleep reactivates the weak new cortical memories formed during the day, strengthening them.
The key to conscious episodic recall is a well formed pattern from the EC/HC to trigger pattern completion.
The functional divide between the cortex and EC/HC is seamless - it allows you to recall episodes throughout the day. The cortex has a exponential decay rate that drops a memory below consciousness in minutes without refreshing. The EC/HC can access these weak traces anytime during the day, and hammers on them with spindle waves to make them permanent at night.
As far as an agent interacting with the world, watch videos of patients with severely compromised EC/HC. They talk, they reason, they perceive and understand, they move and manipulate space with ease. And after a few minutes they completely forget anything that happened; once it leaves the “here and now” it is gone forever.