Not too dissimilar to the situation of the well known neurosurgical patient Henry Molaison (H.M.) who had very limit long term memory of his childhood and young adulthood but little after surgery at 27 years of age. He retained cognitive abilities and self-consciousness but within a narrow temporal world.

Good at cross/word puzzles and conversations of specific types.

https://en.wikipedia.org/wiki/Henry_Molaison