My iMac is alive?

[Dust Mop]

Drinking my morning coffee and watching the rain my attention was grabbed by my iMac suddenly coming to life? The energy saver is not set to turn on or off, but there was the computer behaving as though as I had just turned it on.

Maybe this isn't the place to ask this question, but I am not comfortable with such unwanted activity and wonder if anybody else has had such an event?

 

[simsaladimbamba]

What exact iMac with what Mac OSX version do you use?
And did it turn itself on when it was actually powered off or did it just wake from being asleep?
Have you looked at Applications / Utilities / Console yet?

 

[iJohnHenry]

You know when a cat brushes-up against you for attention?

Same thing.

Or maybe you turned on a peripheral, while in Sleep mode?