One day your doing your day to day tasks or you are discussing a topic with a friend and then all of a sudden an idea or an invention comes to mind.
Either you freak out for a second and think to yourself you're some kind of genius and you put the idea into action.
Or you let it go over your head and you carry on with your day.
Then about day, week or even month later that exact same idea is created...

I've had that happen a few times before, and I kicked myself for not acting on it every time. I believe what you're referring to is the "collective mind" concept. I believe experiments with rats were done in reference to this. They had the rats run through a brand new maze a few times in one place - we'll say Australia - and tracked their speed through the maze. Then they gave the same maze to another set of rats in New York we'll say, and recorded their time through it as well. Every time they did this, they found that the 2nd set of rats in the other location would run through the maze faster than the first set - almost as if the experience of the first set of rats was, in a way, "uploaded" to some collective mind that we all have access to. The idea was to show that once something happens once, it's easier for it to happen again, and again, and again, each time easier and quicker than the time before.