All are at least 4 star books, but the best two are Aging Matters by Stevens, as it addresses both aging, purpose and spiritual underpinnings.
and Your Deceptive mind by Novella. It deals with how we think and frailties of thinking/memory. Seldom do we ‘think about how we think’. That illuminates the thinking process.
Personally I find the Audible approach better, as it enables me to listen/absorb while doing necessary but mundane tings like pulling weeds, and walking biking the same old routes.