I'm with you on this one, Leonora!

I hate being late just as much as I hate others being late or not coming and not telling.

I actually once met a couple who had an "official" policy of making it late to events.

I overheard them talking that an event was planned for 7 PM, so they would be there at 8 PM, and I was like WTF, why would you do this?

Maybe I'm wrong, but I believe people who don't announce to others about a change of plans don't just show a massive lack of respect, but they are also trying to show that they are above anyone else and they cannot be bothered with announcing their change of plans. Ugh!