Anyone who has a cat can agree that there is no such thing as sleeping in. Forget about weekends and holidays, cats will wake you up when they want you up. Whether they want to play at 2AM or breakfast at 6, cats are natural alarm clocks. There are literally times where I forget to set my alarm, but I know that in my peaceful sleep, someone will wake me up at the right time.
I am definitely not a fan of waking up early or the loud sound of an alarm clock, but if I had the choice of waking up and hitting snooze, I would rather wake up to a cat sitting on top of my chest, crying into my face. Cats are literally the best and cutest alarm clocks.