Rookie mistake

Well, got up this morning and went to the shop to fix my "rookie mistake". I used a flash light to look in the spark plug hole but couldn't really see very well. Rechecked pictures and was definately convinced I had made a big mistake. I did check piston to valve clearance when I assembled the motor, but thought I must have done it on a piston that was installed in the correct location. So i pull the valve covers intake and left cylinder head. Turns out that the pictures I was looking at were really kinda off angle. Kieth Black HU pistons(at least the ones I have) have the same size valve relief for intake and exhaust. So I just wasted my time and money only to see that the pistons are installed correctly. Rookie mistake # ??? Now I get to order new gaskets. I did find a piece of emery cloth in the intake that was about 1 inch by 1/2 inch long. So I guess it wasn't a list cause. Sorry for the rant.
Jon