Answer:
his hippocampus
Step-by-step explanation:
Hippocampus can be described as the part of the brain structure that is found or embedded deep in the temporal lobe of each of the cerebral cortex.
It is known to be an important part of the cortical region which controls or regulates memory, emotion, learning and motivation.
Its main role is the consolidation of the short term memory to long term memory.
It has been discovered that a damage to this part of the brain structure resulted to memory loss.
In this case, the stroke had by Mateo affected or damaged his hippocampus, so he was unable to remember how to get and return from his new doctors , because the short term memory can not be consolidated to long term memory.