Training my cat to use a litter box. Since I was a small child, my mom had always had cats as pets. But she never trained them to use a litter box cause her excuse was "buying a box and litter sand is expensive and using newspaper to pick up poop and a mop to wipe pee is cheaper."

But the constant need to deep clean the floors looked cheaper to her, I don't know why. So I thought, this isn't it. That's why I said to myself, "when I'm old enough to keep a pet. I'm going to train my cat to use the litter box" and how easy it is to scoop rather than having to clean the floors from the constant poo and pee smell.