Consciousness and memory both require communication between different regions of the brain. It’s entirely possible that you were "alert’ amd responsive while still suffering a brain injury that prevented you from remembering any part of it.

Anesthesia scares me for similar reasons. It halts the communication between different brain regions, and we know that people have no memories while under general Anesthesia, but are they lying there unable to move, suffering extreme agony throughout the surgery, and just unable to remember it afterwards?