Oscar Wilde once wrote that "punctuality is the thief of time." While you may have to sacrifice something in your life to make your appointments on time, being 10 minutes late for everything steals time from everyone else.
Consider the doctor's office for a moment. The first patient of the day is late, and although your appointment isn't until hours later, it's still your problem. That one person's delay can create a sweeping domino effect on all successive patients' schedules. That's the trouble with tardiness: It's intrusive, and it's rude.
Being late not only wastes everyone's time, it implies your time is more important than that of those waiting for you — whether that's the truth or not. The offending lateness could also be perceived as a calculated way of getting the upper hand or control of a situation.
Being late, for some people, though, is far from deliberate, although it's still aggravating to those who equate punctuality with good character. People who are chronically tardy often share other personality traits, including tendencies to be anxious or easily distracted. And sleep psychologists have discovered that people who are night owls tend to be less punctual than those who are early birds [source: Werner]. In fact, many of us are late because we suffer from something called the planning fallacy. That just means we're all ridiculously bad at judging how long it will take us to complete our daily to-do list. Just how bad? On average, we underestimate the duration of and effort needed for a task by 40 percent [source: MacDonald]. So try to be honest with your time, and make an effort to be punctual — it keeps the world running on time.