Seeing the forest for the trees?

Can anyone tell me what the phrase means?

I believe the correct phrase is being unable to see the forest for the trees. It means you’re missing the big picture because you’re so focused on the details.

I can’t see the forest because all these damn trees are in the way.
Like mstay said, too focused on the small shit, to get the big picture. Either that, or just plain clueless.

An example of usage:

On the argument over global warming as caused by humans: Maybe we are maybe we aren’t, but littering is illegal so it’s irrelevant. Arguing over whether global warming is or isn’t a human issue is missing the forrest for all the trees. Either let me smear my bubble gum across the window of every house on the block, or you’re going to have to limit unnecesary pollution.