One day while gardening, greg tripped over a coil of wound-up hose and fell face first on the pavement. he suffered damage to his hippocampal region, and while recovering in the hospital, he consistently greeted his friends and family as though he was seeing them again for the first time in a long time. greg often forgot what he was doing during the day. however, he could still recall, without effort, adventures from his teenage years. most likely, greg has what would be called

anterograde amnesia

Explanation:

Here, Greg is not being able to recall new memories but remembers his old memories. This is a case of anterograde amnesia.

People who have anterograde amnesia lose their explicit memory (declarative memory) but retain their procedural memory.

Procedural memory is the memory which is in the background of a person's conciousness. For example, writing your signature is considered as procedural memory.

answer; john stuart mill's principle of utility is your answer; /// good luck