Are you sure that everything that you do is authentic?
If you react furious and out of control when someone insults you, is this the real you?
If you wake up and follow your daily morning habit reading a book, is this in any other way more authentic than going for a walk?
Is the intention to get a girl into bed different than the intention to make her happy, although they are both intentions to manipulate?

To anwer these questions, you have to know who you are or at least what you are not. Many people try to answer these questions, yet many confuse integrity with authenticity. Integrity means acting according to your own values beyond your desires and being honest. This is an important step to reach authenticity, but it's not authenticity itself. Nobody is authentic, because nobody knows who he is. Who are you? - many philosophers asked this question and few come to understand ..... they went on asking and asking this question and everything they found was nothing, pure awareness.
Just give yourself new parents, new beliefs or a blemished face, make yourself into a a hindu, a musician, a rapist, a nerd. And you see there is something that never changes....and how can something that is always changeable be you? Your worldy interactions depend on these superficial personalities but they are not you.
But what does that mean about our behaviour?
It means that everything our EGO, our false identification with the self, does is inauthentic.
This approach may seem a bit unpractical at first, because it shows that everything in life that you always did was inauthentic. But it will point you towards a direction that will bring you fulfillment, joy and lasting peace.
Because you identify with the ego you will make the egos beliefs and actions into "authentic" beliefs and actions.
Take the craving for success for example: In the meantime it's common knowledge that success is not going to make you happy, far from it, it will make you miserable because with accomplishement the hope is also gone. This idea that success makes you happy is grounded in the opinions of others. And how can make you something happy that is not authentic?
People think it's themselves, but social conditioning has done a good job.
The only thing that can make you happy is your relationship with the present moment. It means doing something for the pure joy of doing it remote from achieving goals for a REASON. The marketplace is useful for survival but not for your heart and fullfilment.
That of course means that having success is not a bad thing and if it happens when you walk along your way embrace it and use it's opportunities.
Is the intention to get a girl into bed different than the intention to make her happy, although they are both intentions to manipulate?
95% of all guys have the intention/want to fuck beautiful women when they start interacting with them. Most compromise their values more or less. It does really not make that much of a difference if you bring up your gameplan or not. But the trick is to keep to your values and just have fun. Synchronicity is the best game plan there is. And collecting fucks with awful chicks is leading you nowhere at all. Try to understand women and talk to them in a way that responds to their attraction mechanism AND their heart. Learning to make women happy and satisfy them on every level is NOT manipulation because it is in alignment with love (but it can be, you must be honest to yourself, love or fear?). Nor is it inauthentic, because your ego cannot be nurtured by it, it does not gain anything. Love is a sharing and ironically this will make your girls addicted to you. Actually everybody only tries to understand himself more, self-realization is the most basic need and with this the magic happens. Your interest for enjoying pure sex without responsibilities will diminish, because you know your drives are just tricking you into survival and replication.
If you wake up and follow your daily morning habit reading a book, is this in any other way more authentic than going for a walk?
What do you enjoy more going for a walk or reading a book?
Again, the question is about integrity, because if you where authentic you would problably walk around like a buddha doing nothing than acts of compassion.
Which one is more in alignment with heart-centered values?
If you feel rested and excited about the book read it no matter how stupid the book is.
Maybe you would enjoy taking a walk but it is not in alignment with your long-term goals of being an educated man or woman so you choose proactivity and read the book.
If you react furious and out of control when someone insults you, is this the real you?
Reacting like a raging bull, taking out a sword and playing kill bill cannot be authentic neither sitting still getting a red head and surpressing feelings. You are authentic if you don't FEEL anything at all besides compassion. When someone calls you a butthole, you are angry because you think on some level it's true and you identify with being a cool ever perfect guy. Your sense of self is threatened, otherwise there would be no emotional protection mechanism.
How can you identify yourself with being a dirty part of your back that only produces some wastage? It's not even not helpful but also illogical ;-).
Why identify with ANYTHING? A name etc is useful, but that's it, there's no reason to attach a sense of self to a name.
Are you sure that everything that you do is authentic?
The ego is behind most of our actions, even the desire to become non-desirous is a desire. Embrace your ego it has made survival possible. But every time it tries to bother you with some bullshit you can now clearly see that this is based on an illusion, keeping you trapped in some weird game called life, watch it and let it go. You cannot unidentify with something by identifing yourself with the counterpart. Always accept it, make fun of it, watch it and the identification will dissapear. I'm still trying with this stuff, and it's not as easy as it seems.