My high school teacher has literally sent us an email about classroom change instead of walking from one building to another and tell us in person.

Hey, if you're not using technology to save time, then you're using it the wrong way. xD

I used to lecture and this makes perfect sense:

1. Not everyone listens
2. Not everyone is present
3. If it's not in writing, people use it as an excuse
And bonus number 4:
Even when you email it, people still won't get the message