What's the deal with the Calibration tool?

Every time I go through all the steps, I get to the end, click done and it changes! It always goes darker and changes from what the final settings were until I got to the end and named it. Every single freakin time! Then when I click back to go back to where it wasn't changed, the changes remain the same, and the gamma works less and less.. so the image gets darker and darker each time I try to go back and make it work.

I don't get it. What's the trick to this stupid tool?

via ehMac.ca http://ift.tt/2cSAk5g