Back when my old kitty Vega was still with us she'd sit by the front window of our apartment and look out. Apparently this really bothered our upstairs neighbor's boyfriend; I happened to overhear that it really "freaked him out" that she'd just sit there and stare out the window "like she was high or something."
In her younger days, on hazy nights, she and the gang would loiter out in the alleyway, smoking stolen cigarettes in the yellow glow of streetlights, sneering at the uneasy adults who hurried past them on the way to their jobs, homes, and social events. Nowadays, on those same misty nights, she lights up a joint, inhaling and exhaling slowly, then gazes out the window, remembering her past, wishing and hoping that the man upstairs would pass close enough for her to get the jump on him. She would do anything to feel that thrill again.
...Or, she's just a cat. Who stares out windows because that's what cats do.