Every excuse is a small loan against your reputation. The interest adds up fast.

Reputation gets built in small repayments and lost the same way. One explanation is fine, and people accept it, but each one draws a little on the belief that you do what you say, and nobody tells you the balance. Eventually the excuse arrives before the listener has finished expecting it. The decline is gradual, which is why it goes unnoticed until it costs something.

Stop explaining the small things and change one of them instead. If you will be late, send word early rather than the reason afterwards. Then make the next three on time.