That damn Quick Mask

 For more than 10 years, the Quick Mask function in Photoshop has caused me endless frustration. When using Photoshop LE in Windows, you push Ctrl Q to exit the program, but if you forget the Ctrl, you end up with a damn Quick Mask, and I never knew how to get rid of the friggin red layer. I'd go into layers, click show Quick Mask and select remove Quick Mask, but it never went away. I saved copy after copy of my files, and rebuilt the files by copying the separate layers into a new file, just to avoid the mask.

I just now discovered the solution: All you do is press Q again, so it puts a marquee around everything, then click anywhere to deselect the mask. When you save the file, the red layer will be gone.