Got any idea?

It frustrates me sometimes when I see simple ideas making millions of dollars.  I just say to myself, how did I not come up with that?  Literally you say to yourself, how could that person possibly come up with that idea and not myself.  I use the same thing everyday but I guess this person just realized that using the same everyday could be easier and that's exactly what they did.  See like a couple days ago, I saw one of my friends on Facebook post something about a new way to build roads.  Basically, it was like one of those dance games you would play and you would have to hit the square that lit up on the screen with the one on the floor.  Smart idea really because now everything on the road could be seen.  When a deer is on the road, when a person is on the street, street lines wouldn't have to be painted.  The list went on and on why this new approach to building roads would be beneficial.  And I had come up with something similar way back when.  I live near McMaster University and there is one crosswalk that students cross all the time but in the dark it can be nearly impossible to see them.  So I thought to myself wouldn't it be cool if I could come up with something that when students crossed the road a light on the street would brighten up so you could tell something was crossing the road, whether that was a student or some other foreign creature.  I thought about it and basically shut down my own idea because of all the bad things about it.  For one, it would be extremely expensive to do this.  There was no cheap way of installing this concept.  Second was due to our location.  We live in Canada where there is snow.  What would happen when 2 feet of snow would fall on this sensors.  People wouldn't be able to see them, it just didn't seem realistic.  And now I see my idea being put to action years later.  Now of course they are faced with more challenges and have come up with more concepts of how to use the technology, but the fact that I know people are thinking alike gives me a confidence booster because I know sometime down the road one of my billion dollar ideas will come true.