There is obviously a big difference in how it is determined where you sit at work between your office and mine. I have my own office. It has my computer, my files, pictures of my children, my hand lotion and my coffee mug that I forgot to wash out last week. If I come to work at 5 a.m. one day, I don't decide that I will sit in my coworker's office, even though it is bigger, where I will use her computer, look at pictures of her son, use her mug, and snack on her pretzles. I come to my own office.
Why does my coworker have a bigger office? She has been with the company for 9 years. I have been here a little over one year.