How people respond to life-changing inventions:

1. I’ve never heard of it.
2. I’ve heard of it but don’t understand it.
3. I understand it, but I don’t see how it’s useful.
4. I see how it could be fun for rich people, but not me.
5. I use it, but it’s just a toy.
6. It’s becoming more useful for me.
7. I use it all the time.
8. I could not imagine life without it.
9. Seriously, people lived without it?

(via kottke)