Suspiciously close to a 32bit integer maximum value in milliseconds (232/1000/60/60=1193 hours)
Maybe you listened to roughly 1 hour or had roughly 1 hour left and some sort of integer overflow happened that set the remaining time to integer maximum+listened time/time left














It woild never happen as shampoo is meant for not just hair, but oily hair.
Even if you had the hariest of backs, it would probably be overall better for you to use soap.