When you look at it from the perspective of personal energy, “being nice” is actually disempowering on multiple important levels. For one, you aren’t actually being “you”. You are playing some role that you feel you should play. That keeps you from being truly known by other people and from knowing yourself. You just live a lie.
On a deeper level, you are putting your own desires and goals and preferences on hold for other people. Why? Aren’t you worth having your own opinions and desires? If you don’t stand up for yourself, who will? You have to be your own advocate in this life…and besides…we only have this one life to live this time around, so LIVE IT rather than letting it pass you by!
And on an energetic level, when you claim your power, your opinions, and trust your instincts, you hook into the flow of the energy of creativity and manifestation. Coincidences start happening. Doors start closing and opening. Things shift for the ultimate better.