There is the theory that there is no such thing as coincidence. Similar to the whole thoughts are intentions notion or thoughts manifesting into something real,is that occurance where you think of someone you haven't seen for a long time and the next day you happen to decide to take the long way home and guess who you are likely to meet on the way.

Another example when you choose to do something mentally and you suddenly meet someone who helps you on that path.

Or another example when you think of someone you haven't spoken to for ages, decide to call them and they happen to be on the same path you are on or you can help each in some way to progress.

Coincidence???

This school of thought suggests that this person (or thing that happens to occur) could happen to change the course of your life or they have something important to show or tell you to advance your life path so it shouldn't be taken lightly. It could be the smallest thing but it also comes into line with that whole butterfly effect theory as it can change the course of something no matter how meaningless it may seem at the time.

Apparently this sort of thing happens all the time but we either dismiss it as coincidence or choose not to take the hint that our thoughts has been trying to convey.

I suppose this same school of thought can apply with instant changes and patterns of interactions between people. Your true thoughts can manifest in the way you talk to people even if you are polite. Just when people just don't like other people's vibe. It can't always be incorrect, or simple coincidence.