Stupid is as stupid does

I just finished putting in the last drawer slide - a pain in the ass - why didn't I do that before the counter top went on?  I knew I should have done it as I was installing the top but I was anxious.  Anyway the slides are in and I went to slide the drawer and it didn't fit.  How could this be - I measured and then measured again.  Hell, as anal as I am I probably measured 3 times - yep it's good.  I made the drawer the same size as the opening - I apparently I didn't subtract the 1 inch - stupid, stupid....

get the orange paint back out Deb