Someone's been sitting in my chair....

So someone's been sitting in my seat at work. I know who it is too. But he's new, so I shouldn't get all cranky at him. BUT.... he ate my pistachios and left some of the shells in the bag to make it still look full. And my keyboard had gooey marks on some of the keys. Argh. The big, bad, Sheila-bear is going to get angry soon. I'll be the first to admit, I'm very territorial about my space. Especially my space at work, since it's such a small area that I can call my own. And for heaven's sake - eating my snacks?!?!? Where have all the manners gone?