I've only read about half this book, but will risk (Osho-like) a review of it. I've somehow got the impression that if you've read one book by Osho, you've read them all. Of course, that's not *entirely* true, but the seemingly endless stream of Osho books does contain many titles that are very repetitive.
So what is the meaning of life, then? Osho explicitly says that there is no answer to the question. Instead, the task is to make the question go away. This is accomplished by meditation. If you meditate hard and long enough, the question will dissolve. Indeed, you will eventually realize that it was a ridiculous question to begin with. Meditation gets us in touch with reality as it actually looks like. Once this stage is reached, there will be no need for silly questions about the ultimate meaning of life.
Osho's metaphysics (if that's the right word for it) are based on Buddhism. Humans have no soul, yet reincarnation happen. Like the Buddhists, Osho compares human life to a candle flame. If you lit a candle in the morning, is it still the same flame in the evening? Both yes and no. If you take the candle and lit another candle with its flame, is *that* the same candle, or another one? Again, both yes and no. This is how reincarnation works: a never ending process in which we die and are reborn at every moment.
Within Buddhism, this process is often taken to mean that humans must "liberate" themselves from the cycle of reincarnation, instead entering the state (or non-state?) known as nirvana, of which nothing positive can be said. Here, Osho parts with Buddhism - at least Theravada Buddhism - and instead suggests that our liberation consists in being able to live fully in the here and now. Judging by some of Osho's other books, his vision is one of hedonistic ribaldry. He reminds me of a relic of the hippie age. There is also a strong, anti-establishmentarian undertone in his message. Religious leaders, politicians and educators are all part of the enemy.
Osho was an antinomian sage, perhaps very loosely inspired by certain antinomian tendencies within Hinduism and Buddhism, but above all with a message geared towards Westerners fed up with the grey status quo. Indeed, most of his followers have always been Western, not Indian.
Osho himself (then known as Bhagwan Shree Rajneesh) ended up rather badly, turning into a cult leader in Oregon, where he surrounded himself with some really unsavoury characters. However, the hedonistic-meditative message is problematic even as it stands. Sure, I don't deny that it "works": if you meditate like crazy, all those annoying questions will indeed go away.
But then what?
Somehow, I don't think joining a hippie commune or artists' collective sounds like a credible solution to anything. Even apart from feeling hopelessly anachronistic...