See if this helps... While there are sharp spikes, they are not up against the right hand side and also not too high up on the scale. Also, notice how the middle of the histogram got fatter? That means more data is now visible in that range of grays (yes, they are all grays per layer of color :tongue:)
Everything I learned about histograms and color correction after much reading on the subject, was from the great Dan Margulis. I suggest you read him and learn a lot about how digital data is stored and used to represent real world scenes. Absolutely great learning from any of his books. The ...Canyon Conundrum... being my favorite!
His recent Picture Postcard Workflow is a terrific video tutorial from what I hear (have not had the pleasure...)
http://www.danmargulis.it/index.html