Tardiness, my own or someone else's, is a HUGE pet peeve of mine. I hate being late for anything, and I absolutely hate standing around waiting for someone else who is late.
Every minute someone is late is a minute of my time they are wasting. If I had known they were going to be 5, 10, or 15 minutes late, that's 5, 10, or 15 minutes I could have been doing something else. Realizing this, I don't want to be the one to waste other people's time. It's rude.
A guy once said, and it is very nicely worded, that you only have 1 minute to be on time. Everything else is either early or late, so never be on time, and always be early. I usually run a minimum of 5 minutes ahead, and never more than 10. I know how long it takes to get from point A to point Z in the frayed morning, in the lazy afternoon, and in the crush of evening rush-hour. I'm constantly timing how long it takes me to walk from a class to somewhere else on campus, and from the front gate to a destination on school grounds.
The biggest problem in China is not the teachers being late - it's the students.
In all, if I ever say "I'm 10 minutes away" from arrival, I know what I'm talking about. Call it an obsession, but for the life of me it's been one of the toughest things to get used to in this culture. No one is on time here. Classes start at 2:00, but that's about the time the students start thinking about coming to class. When 2:00 rolls around, I'm lucky to have 3 students present in the room. The rest trickle in over the next 15 minutes. It's aggravating.
