Yes I came here to post this one as well, together with Narziss and Goldmund and Steppenwolf - I read all of them in a pretty short period. There is a sort of common theme where Hesse explores the trade-offs between a life of thinking vs a life of feeling (most obviously in Narziss and Goldmund) which at that time meant a lot to me. I can't think of another author whose work resonated in the same way, though I'm not sure I would have the same experience rereading the books now.