According to my mother, when my father was dating my mother, they did a lot together. They went to dances. They went to the movies. They went on picnics. After marriage, my father soon settled back into a routine -- go to work (When he had work. Although a very hard worker, since he had only a ninth grade education, he was usually on the queue to be first let go), come home, eat dinner, and settle down in front of the television. And so the days went. Our family went on a vacation once in my childhood -- a camping trip with my aunt and uncle and cousins. We did not stay the full planned length of time -- some type of argument. This was not the life that my mother had expected within the marriage.
When most of us approach a job interview, we are asking ourselves "what do they want to see in a candidate for the position?". Yes, the interview should be mutual but it often isn't seen that way by one party or the other or both. There is nothing wrong with trying to present one's best behavior and attitude in an interview (or a date, or ...) as long as it is still within the range of behaviors that you would normally do. But trying to present an image of someone you are not is a mistake. Strive towards that mutual interview where you are discovering what the company is and they are discovering who you are.
Unless you are applying for a role in a movie or play production, it is not a good idea to pretend to be someone that you are not. Look at the situation from a long-term basis. Can you, and do you WANT to, present that person for the next 20 years? It is a tried-and-true technique, for personal behavior modification, to "fake it until you make it" but that doesn't work if you do NOT want to shift behavior in that direction. You are more likely to be tired, irritable, and angry.
If you bring a smile to your face each morning, it is difficult to not have that influence your mood. If you glower at your workmates each morning as you arrive, don't be surprised if they start becoming hard to find in the morning.
Dating advice often says to do things you like to do in order to meet other people who also like to do those things. But often we will find our eye drawn to those who do those things that we idealize as things we would like to do, think we should do, and admire others who do them. As an example, you admire someone who exercises on a regular basis and has a good awareness of their body to properly eat. If you are not of the same mindset then you should NOT try to be involved with that person as it is a conflict that is not likely to change. (Note that it can work if priorities are not the same for both; if one person has a high priority of financial security and the other has a high priority of aesthetic achievement then incompatibility can still achieve personal goals.)
In general, be the person you are most comfortable being. Don't expect to be able to change others (you can't) and if others want you to change then determine what you, yourself, want to do. They can't change you but you can (if sufficiently motivated) change yourself.
Accept that being the best you, that is natural for you to be, is good enough.
