Think about this: How you "know" yourself is how you understand others.
Remember that for next time you interpret someone else's intentions/actions or next time you make a judgement about someone. Because what you see in people is merely a mirror of yourself. Everything you see or know about people and their ways can only be so by knowing it in yourself first, be it a past self, current self or imagined self.
It's important to realise because it basically defines all of your interactions.
Consider this: If you love yourself you will see only love. If you don't like yourself then you won't like others. If you act with integrity then you will see the positive intent in others. If you don't trust yourself then you wont trust others. If you are connected to yourself then you will easily connect with others, etc etc.
The way you interpret people is merely a reflection of your own ways. And the way you feel about people is a reflection of the way you feel about yourself. And the way you judge others is a reflection of the way you judge yourself.
This is the plain and simple truth.
How do you perceive people in general? Assess that, accept what you learn, then make the change.
Consciousness is a mirror. Do you like what you see in the mirror? If not, change the way you habitually think, and the way you feel about yourself, towards the POSITIVE, and towards love-based perceptions (not fear-based), and watch a whole new world of beauty open up, simply because of the way you inadvertently perceive it. Everybody deserves to.
In actuality, most people DO have a strong sense of self, and a sense of understanding of others, probably more than we realise. We actually do know ourselves and others more than we think. It's worth giving credit where credit is due. We go alright! However, there are times when you will misinterpret people due to ignorance of that quality or value that the person might hold. It's important to accept this and therefore be open to learning about the perspectives of others. Two people can have a seemingly flowing conversation and not actually be on the same page, or actually be talking about the same thing. Are you completely ignorant to some of the positive values and thoughts people display? The thing is, you can never know, unless you do. So open yourself up to the new perspectives of others or forever stagnate in a pool of your own thinking habits and perceptions!
So if you want to be around positive people and vibes, then what you have to do is change yourself towards the positive. Everybody in the world has both positive and negative aspects to them, it just depends on what you focus on the most. So if you change yourself, then you change your reality. You will subconsciously give your attention to the aspects in people that are most like yourself. So observe it. Learn it. Accept it. Change it. Be the person you want to know.
The old quote is true - "If you don't go within, you go without"