Thinking ourselves into an enlightened state is a particularly clever way of countering the negative tendencies of the mind; it cuts right to the root of our contracted feelings. The real cause of fear, of anger, of addiction, is the feeling of being alone and separate from everything. Any moment that we can shift that viewpoint, we eliminate a layer or two of fear and anger. The more we can do that, the more we shift the neuronal pathways that create anger, fear, and all the other "enemies" of our happiness.
Practicing enlightenment, thinking "as if" you were an enlightened sage, is one of the world's most sophisticated exercises in "fake it till you make it." Of course, it only works when we do it for its own sake, not because we're trying to impress people, not because we're pretending to be something we're not, and definitely not in order to claim mastery we don't possess. We do it the way kids pretend to do grown-up things—because it habituates us to the mature self we will one day become.
The truth is, we all hold inside us a template for enlightenment. Whether we call it the Self, or Buddha Nature, there is at the core of us something that is, effortlessly, happy, peaceful, and utterly connected to all-that-is. Every time we remember oneness, we bring ourselves one step closer to experiencing that core self. It's a bit like calling forth the enlightened sage who lives inside us. The sage is really there, along with all the other sub-personalities: the whiner, the charmer, the worrier, the one who stays up nights watching TV, the kick-butt yogi. The more you can align yourself with the sage, the more the ease and freedom that your inner sage possesses will color your life.