Books that make you think about life on a deeper level

Hi,

I used to read a lot but I haven't read anything for a long time now since I've been so busy with life. I'm finally at a place where I have some free time and would love to pick up a book. A book that makes me think about life on a deeper level. About life, relationships, purpose, anything. Book that says stuff that I can think through during my cold night walks.

I know this might be a crazy ask but anyone got something like that?