When you give mate but still don't know it's already mate.

What i have noticed is that quite often it's bishop which either delivers the "unexcepted" check or blocks the king. At least for me that's often the case. It's many times so far away you almost forget it's there, waiting to fullfill it's destiny : ).

This thread is an excellent idea. Haha!
I had some some examples, but can't find them now.