Mice come into your home searching for food and warmth.
Even when you have a clean house it's still possible to get some mice coming into your house in search of food.
I keep my house clean, counters clean, my floors clean and dishes all clean and still have mice come into my house once in awhile.
I don't have a mouse infestation because I trap them and kill them as soon as I notice them and keep food put up away from the mice.
If you have a dirtier house and crumbs of food laying around etc then you're more likely to get mice but even with a very clean home you still can get mice.