I have been blissfully unaware of this term until recently. Growing up, wearing a pair of 'slippers', as we call them, is a must around the house. Cheap. Rubber. Think $1 a pair Old Navy type.
And if you are going outside, you have a different pair for that. You don't want the dirt from outside to get on the recently cleaned floor.
And we wore them everywhere. Walking. Biking. Impromptu pick up basketball games. It was the tropics.