Can you recover from brain-injury?

Yes and no: There is a "s" curve of recovery. Recovery may stall or be slow at first, then pick up sharply with remarkable effect, but then slow again short of full recovery. Careful directed therapy, careful use of medications, and good motivation all play a part in how complete the recovery may become.

Agree yes and no: Depends on severity - the more severe the injury - especially w/ lower glasgow coma scale scores, prolonged amnesia, internal bleeding, herniation, complications of hypoxia or anoxia, post-injury persisting seizures etc suggest there will be some permanent reisdual the extent of which will require neuropsychological and neurological assessment. Mild concussions can, but not always recover well.