Books that stay with you...

What are the books that have stayed with you for years or even decades after reading them?

I have always read voraciously, ever since I was a child, and now I'm in my 30s I find that the details of the books I read quickly become hazy and I forget big chunks of them very quickly - character names, details of events etc - and only really remember the general feeling and main plot points (sometimes not even those!).

However, there are always those stand out books that, for whatever reason, stick around in my head for much longer. I wouldn't necessarily be able to tell you what most of the books I read last year were about in any major detail, but I can recall certain books that I read 15 years ago with amazing clarity, even if I read them only once!

I'm curious - what books do this for you, what do you love about them?
Are any of them books that you wouldn't ordinarily pick up to read?

Books on this list for me:

• The Long Way to a Small, Angry Planet by Becky Chambers
• Flowers for Algernon by Daniel Keyes
• Noughts & Crosses by Malorie Blackman (I think I was about 12 when I read this!)
• All the Bright Places by Jennifer Niven
• The Poisonwood Bible by Barbara Kingsolver (I was about 18 when I read this - was definitely not my usual choice at the time).
• The Humans by Matt Haig