It's nearly impossible to keep negative statements and negative attitudes from sticking in our mind somehow. Even if you know they are not right, you exert a certain amount of energy on the negativity. I generally don't shy away from people and have always been quite tolerant of people who could be difficult to deal with. Those relationships are not positive. They drain energy. Stay in that place and it will feel like a whirlpool - churning and churning in a circle that goes nowhere.
Get around positive people with positive attitudes and the energy grows - yours, theirs and a new collective energy. Positive people overcome challenges, create a shared vision, and get things done. They possess qualities of thankfulness, recognition of the contributions of others, clarity of purpose. When they throw a stone in the pond, the ripples never stop doing more good.
The most important thing positive people demonstrate is the understanding and the skills required to build and maintain healthy relationships. When they walk in a room, people take notice and want to be near them. They lift the mood. That's who I want to be and who I want to be around.