- Intrinsic Happiness
I do not consider the "intrinsic happiness" to be "true and higher-level happiness." Instead, I consider it a "pleasant nature" that enables the people to experience happiness more. Most likely (and unfortunately), we have all seen some "unpleasant nature" that tends to spoil the good moments of life and aggravate the challenging times. The "intrinsic happiness" is just the opposite of that.
- Nice? Maybe Not
While reading your response, I realized that "workplace" might very well be one word by itself. And, wiktionary seems to agree. Let me change that.
I agree with your expectation of the boss and colleagues. However, I challenge you to prove that it is possible to achieve "I am always nice, because it is my nature." To me, it seems inevitable that one has to be not nice from time to time, especially from some other people's perspective.