Part One is the Holocaust account. As one should expect, terribly tragic and poignant. I've read much about the Holocaust, but this one is different because it adds some psychological analyses. The central one is meditating on the will to carry on. Because what could be worse than the actual Holocaust? That's what this book is all about after all, meaning. Part Two is where Frankl expounds on his Logotherapy, which looks to the future as opposed to psycho-analysis, which is retrospective and introspective. I found that the clinical language really resonated with me, as did the case for tragic optimism.
The real standout heading for me is The Existential Vacuum in Part Two. It mentions man's loss of traditions and then goes on to talk about "Sunday neurosis" (what we now call colloquially "The Sunday Scaries").