I don't understand.  I love chess mentor but when I check the difficulty during a lesson I lose like 3% percentage points.  Don't get me wrong, I'm not complaining, just wondering why this happens when you can see the rating on the list of lessons at the start.  Surely checking it shouldn't be grounds for penalization?

It's a hint. Knowing the difficulty level can help you find the answer.

its a hint!

Yeah, but like I said, if I just go back to the lesson list it tells me the difficulty there.  If it didn't, I would understand it was because it was a hint.  But if I really want to find out, I can.  I just usually can't be bothered to check, so I check during the lesson.  But when the info is available, albeit at the cost of a couple of clicks, its hardly a secret.  I just find it strange is all.  It doesn't tell me the key squares or the correct piece on the lesson list screen, so it makes sense that they are hints.