Noah’s Compass by Anne Tyler

Liam Pennywell, who set out to be a philosopher and ended up teaching fifth grade, never much liked the job at that run-down private school, so early retirement doesn’t bother him. But he is troubled by his inability to remember anything about the first night that he moved into his new and spare condominium on the outskirts of Baltimore. All he knows when he wakes up the next day in the hospital is that his head is sore and bandaged. His effort to recover the moments of his life that have been stolen from him leads him on an unexpected detour. What he needs is someone who can do the remembering for him. What he gets is . . . well, something quite different.