My dad's copy of The Road had one line underlined and I finally get why

I found my dad's old paperback of The Road while cleaning out his garage in Toledo last month, and he had underlined one line about carrying the fire. He passed 6 years ago and we never really talked about books, so seeing his handwriting in the margins hit me harder than the book itself did when I first read it at 19. I sat on the garage floor for like 20 minutes just flipping through pages, and there were little pencil marks all through the ending. It made me wonder what he was going through when he read it, since he never once mentioned it to me. Has anyone else found a book that belonged to someone and felt like you were reading it for the first time again?