My boss asked why I keep leaving at 5 PM exactly

Pretty sure he was testing me when he asked why I'm 'always rushing out' at 5. I told him straight up - I have kids. Daycare closes at 5:30. If I'm late I get charged 1 dollar per minute. That's 30 bucks if I'm 5 minutes late. So yeah I leave exactly at 5 and I'm proud of it. If the work isn't done by then that's a time management problem, not a me problem. He didn't have a comeback for that one.