Be sure the Histogram window is open in the Palette Bin.
The histogram is a graph of all pixel RGB values moving from pure black on the left to pure white on the right.
An image with a lot of dark pixels will show a mountain on the left, and vice versa if it has a lot of light pixels.
Where will the mountain be if the image has a lot of midtones?
Where will the mountain be if the image has a lot of dark pixels, a lot of light pixels, and almost no midtones?
If the image has a lot of pure black pixels part of the dark mountain will have slid past the left edge, and vice versa if it has a lot of pure white pixels.
There is no “correct” histogram, any more than there is a “correct” exposure. Histograms only show you what is there. “Correctness” is your decision