You know how almost everything is a remix and there aren't any truly original ideas? Knowing this, that means that nine times out of ten your idea has been made. It won't be an exact match but it will be similar, like sharing the same unique selling points.
Because of this, one can get discouraged when looking up their idea when they see something similar has been done. Sure, this shouldn't influence them like that because your game is nearly always quite different than one that is quite similar. It just always gets me depressed when there is a game I want to make and I can play the same game immediately and dump my idea right then.
However, it could also be a good idea to look up your game concept because you can research if it's fun or not, how well the crowd accepted it, and what is good/bad.
Should you search your game concept on the internet?