Photoshop :: CS6 / Local Adjustment Slider Settings Retained Even When Cancelling Out Of ACR

When working on an image in ACR, if you select one of the local adjustment tabs, such as Graduated Filter, and move any of the sliders on the right-hand side, any values you change will be retained if pressing 'Cancel', then opening the image again in ACR and selecting the same tab. I find this surprising, as I would have thought that by pressing 'Cancel', any adjusted settings, since opening the image on this occasion in ACR, would not be retained.
 
Furthermore, if you open another image in ACR and select the same local adjustment tab, the same settings that you adjusted in the other image have identical slider settings in that image as well.
 
I can see that this behaviour could be viewed as useful, i.e. when wanting to use the same local adjustment on multiple images, as any adjustment of the local adjustment's slider settings, on their own, will have no effect unless you actually perform the selected local adjustment to the image. But, as I say, I would have expected Photoshop to simply not retain any settings you have adjusted, since opening the image on this occasion in ACR, if you don't press 'Open Image' or 'Done', and simply press 'Cancel'.