I have absolutely no clue as to what is happening to my document. I have never experienced this type of problem with a program before. I have one page in my document that when you type text the alignment options (Align left, align right, etc.) automatically uses the option to automatically Align away from spine. Even when you change it to left align it continues to keep the text away from the right edge of the page. When you select the option to "Justify with last line aligned left" the letters spread out across the line. The first letter starts on the far left of the page, then second letter you type goes to the far right, the third goes to the middle of the page and so on it goes until you can only fit three words on a line. Anyone have any clue as to what is happening?
Version of InDesign and OS?
Are you doing this all by keyboard shortcut, or does it behave the same if you use the buttons on the control panel?
If by keyboard shortcut the symptoms could be possibly either that you've changed shorcut sets or possibly that you have enabled a different language keyboard. The fact that it's restricted to one page in one file, though, sounds more like document corruption of some sort. You could start by exporting to iinterchange format to see if that fixes things: Remove minor corruption by exporting
You could also try deleting that page and replacing it with a new one.