Why make plans in the first place then? Changing plans at the last minute is really inconsiderate behavior.
Of course you are, but tanseydavid thinks he's meeting you in town and doesn't have a phone...
I imagine now it's just straight to the latter, (albeit with less txt spk and more memes & emoji) because children get phones and start making their own plans at about the same age. (And not by coincidence probably - they're arranging to meet friends and going out alone, so parent wants to be able to contact them, to stay in the loop, etc.)
if you find out about something interesting that you didn't know before, why should you not be able to change your plans to go see or do it?
hey, i just got some free tickets for that show, so how about we cancel dinner and go there?
(They weren't allowed actually at school though, weren't even supposed to be in your locker, so I always think it's a bit weird when it occasionally pops up debate about banning them from schools or that X school has banned them - curious when and why they allowed them, or maybe they were just always allowed to begin with?)