ME. I'd know.
Well, of course!
I'm not advocating dishonesty.
I agree that there are times when it would be nice to have the option to turn the thing off - even during the 24 hour countdown to fly.
I'm just saying that if I found myself in a situation where my computer was ON when I boarded the plane (say, because TSA made me turn it on or maybe because there was still 15 minutes left on the to-fly countdown), then I'd have no other choice but to leave it on. In that case, it would just remain in my bag where it usually stays anyway. Since it presents no realistic harm to the plane or anyone else on board, I'd just let the clock run its course and shut itself off. I wouldn't feel a need to point it out to a flight attendant who probably wouldn't understand anyway.