This one transformed and cemented me as a young adult, totally screwing me up and enlightening me at the same time, showing me that living in a crazy christian culture doesn't mean I have to stay there, or that great imagery can be used soooooo damn subversively. :) 
 And above or below that, it was a fantastic tale of striving for wisdom, learning that semantics MEANS something, and that I can be blown away by the fact that so much philosophy and striving and understanding, (read Grok,) could be thrown into one single novel and still be a wild tale. 
 So why all the hate, Ya'll? Oh good ole' Jubal is a stand-in for Heinlein's soapbox tendencies, sure, but he's also a wild character in the sense that he is what he is. He loves women, but says awful things, but on the other hand, these women respect him enough to throw him in the pool and blow raspberries at him, too. As we all should, today, to all men who act as a Mad Man from 1962, all heavy-drinking, heavy-opinions, and "apparently" sexist. But no one really believes that about him when they get to know him. He's a good man and a loudmouth author and all his other progressive ideas like equality between the sexes are SHOWN to us, repeatedly and repeatedly, by actions and deeds and a closer look at all the philosophies. It's the difference between expression and reality. He expresses as the time allows, but in reality he supports everyone. That's Jubal for you. 
 But he's not even the main character, just the most loud one. 
 Mike is. He's an alien, yo, born of man but raised by Martians with heavy-ass psychic powers, yo. And he's innocent of mankind, too. 
 This is his story. Who tries to capitalize on the man who owns Mars, who protects him, how he learns to adapt and later to understand us crazy humans, and what he does with his gifts. 
 The novel could be an indictment of modern times, a brew-on of absurdity when it comes to religion and religious thinking, a wildly prescient vision of the sexual liberation movement just a few years down the road, (or perhaps the seminal novel that informed the sixties love movements,) or it could be a wonderful shout-out to us all to start trying to UNDERSTAND one another, for grok's sake. 
 So I think it's wonderfully delicious. You know. To say that Heinlein is a sexist reactionary? When he, like, is the spirit of the sixties? Huh, water-brother? You Grok? 
 This is easily one of my favorite, if not my most favorite Heinlein, not just because it got into my soul when I was a kid, but because it's just one of those works that lives and breathes and still brings a big smile to my face. :) Oh, and it's one of my top 100 works of all time and it won the Hugo of '62, not that anyone really cares, because it just SPEAKS to so many people. :) 
 That's controversy for you. :)