That was a long time ago, friend... Sorry. 🙁
You can only power on any of the current or recent Macs (going back for the whole decade and then some, I think) from the power button on the unit itself.
If it's sleeping, which you can well do instead of turning it off, you have numerous other options. You can...
- Wake it with a wired or wireless keyboard
- Wake it with a wired or wireless mouse
- Wake it with the Apple remote control
- Etc....