If you see the world as a friendly place, you'll tend to notice goodness. Because you're looking for friendly people and friendly things to happen, you're that much more likely to find them. At times, you may even create them with your intention and your actions.
Conversely if you see the world as unfriendly, you'll likely find exactly what you're looking for. Our beliefs become the filters through which we view the world.
I can't recall where I heard the following story, but it stuck with me. Its a conversation between two people on a plane. Person A is about to move to a new city that Person B is familiar with and asks if the people are nice there. Person B responds with a question - Are the people nice where you're living now? Point of the story is if you believe people are nice in one city, you're probably attracting niceness. Likely as not you will do the same thing in a new city. The converse is also true.
This from the Abraham-Hicks daily quotes......
You are always living a reflection of whatever you are outputting. And so, if you get into a little pocket where a lot of people are being rude, it's probably because you are being rude -- or because you have been aware of people being rude. Nothing ever happens to you that is not part of your vibration!