In the world, there are people who represent the expression in many contexts and are like chameleons, transforming into a different person with each situation. When the goals are selfish, I doubt such metamorphoses would make for a happy existence.
Being genuine (authentic) is the right approach. When authenticity is mixed with kindness, the result is happiness (or sweetness).
Dependability is a virtue and if you happen to have a reliable person who is there for you in bad and good times, then you are absolutely blessed.
Ask anyone who is happy and they will tell you that they are givers and have someone who does not abandon the ship because of a storm but rather weathers it with them.
May one of the constants in our lives be that we are dependable and have dependable people around us.