Because it's annoying as fuck if you set up wireless printing. I'm assuming a PM at Brother thought this would save the planet.
- Go to **General Setup** -> OK
- Scroll with arrow keys to **Ecology** -> OK
- Scroll with arrow keys to **Sleep Time** -> OK
- Set it to 0 minutes -> OK
- Now you have to hold _both_ the back button and down button to see the 'secret' **Deep Sleep** option. Turn it off and you'll see "Accepted".
- Hit OK the appropriate number of times to get back to the main menu