Can't think of any book I've read with that specific focus, but a number of authors come to mind who have opened up my thinking about life in general and my life in particular. Some might surprise you, because most people would not associate anything they wrote as making the reader "stop mid-page to reflect on your life..." but I'll list three of them anyway, because they did that for me, sometimes directly but often indirectly:
Bill Brower, especially his A Short History of Almost Everything
Carl Sagan, especially his Shadows of Ancient Ancestors
E. B. White, especially his Charlotte's Web
You might also read the Disiderata -- not a book but if it doesn't make you stop and reflect on your life, check your pulse!
Biographies, autobiographies and memoirs are also good places to find things that might compel you to reflect on your own life. And you might also consider the possibility of writing your own memoir or autobiography (there is a difference) -- not for publication but to help you discover yourself.
Hope you find some good books and if you do, please pass them on to the rest of us. Thanks,