Wherever your focus is directed, that’s where your energy goes. Whatever you allow in your space, you eventually become.
If you are angry at someone and you direct all that anger and energy towards that person, only gives them more power over you. When you allow yourself to constantly think of that person and what that person means to you or how they make you feel, you allow that negative energy in and you will eventually start to develop some of those bad personality traits you dislike so much. Be careful of carrying grudges around for too long.
However, if you direct that energy to something good and productive, you allow positive energy in and there is nothing better than being happy and having a positive outlook on life! Therefore, the next time you direct your focus somewhere, first make sure that you are focusing your energy on what you want to allow in your space.