Unix is mysterious when you first approach. A little intimidating, too. But despite an unadorned and often plain presentation, the discerning suitor can tell there's lot going on under the surface.
She's complicated, too -- getting to know her takes some effort. She can be a little unforgiving on the command line. And of course, there are the inevitable arguments -- regular expressions, switches, and such -- so you have to choose your words carefully. Eventually you'll realize you're going to need to know a lot about her history before things ever get very far.
But if you show the right level of commitment, you can get close -- much closer than other OSs. When you become a superuser, both you and Unix will be at your most vulnerable. You'll need a steady hand and an even temper to make it work out. And in many Unix relationships, you'll even get source code and a compiler; you can ask her to change for you. A relationship doesn't get any closer or more committed than that.