Confusing

I walk into the room, I pull up my chair, I keep my bag, Then I go out. No one noticed. I walk around the building, I talk with people, I smile at little girls, And whistle to the birds. Then I go back. I walk into the room, and everyone notice, They nod, and I go to my chair. They saw it, but they half smile. There was someone else in my seat. She smiled, Looking for my bag from the corner of her eye. But she didn’t move. So I pick up my bag, and move out. 21/10/2018