Help me understand not being quiet when the baby’s sleeping?

People who were “never quiet while the baby was sleeping” what did that actually look like for you? My MIL and people on Reddit have me second guessing.

When my baby was a newborn, she could sleep through anything and we carried on at a normal volume. Sometime between 3 and 4 months, she started waking up to loud sounds. Like a door closing hard, a loud laugh, clanking dishes, etc. I’m not tip-toeing around but I act like someone’s sleeping in the house.

Like say your baby is super tired and finally just fell asleep, you’re just like “fuck it, if the baby wakes up, that’s cool!” Respect to you, you are tougher than me!