Mouse needed to clear her head. Her younger self and her brothers were sound asleep and her parents were doing whatever it was her parents did at night. She couldn't sleep, though, so she decided to go for a run. It was the best way to clear her head. She could just shut her brain down and run, not worrying about anything but where she was going.
She turned a corner and ran into a light pole. She'd been distracted by the rather attractive shirtless man wandering down the street. Being who she was, more damage was done to the pole than to her, but she did fall back on her ass with an oof.