I am happy that everything is solved in the end. Pay attention to what you are doing every time. I am thinking when I am doing something like this:
-now I get up from my chair
-now I am walking toward the door
-where am I going?
-what am I going to do where I am going
-should I bring something there
-what did I brought here before sitting on the chair
-what do I have in my pockets
-etc
There is a list of things, but you are going through this list very fast, in seconds. Take care and good luck with your exams!