Sometimes it also appears to exhibit pitting (with no visible insects to be found -- though it's unclear, with all the packaging, if some of the pits were developed during manufacturing) and a slightly rancid (?) taste. White chocolate of similar age seems to be less affected. Caramel centers in chocolate seem to dry out with time, leaving a dry residue.

Chocolate can melt in one's hand, but slight cooling can also make it hard enough to damage some dental work. What accounts for such change?

People can lose their sense of sight, hearing, smell and taste.  But can anyone lose all sense of touch?  I suspect this wouldn't happen because the touch sense is distributed throughout the body's nervous system, but wonder if brain damage could cause such a loss.  It seems as though it would be extremely difficult to survive if you couldn't even feel the floor when standing or walking or your chair when sitting.

I was wondering if people that are blind their whole lives have dreams. If they do dream, can they see things or is it just sounds or feelings?

I've heard that your brain calculates the position by the time difference between the sound reaching one ear and the other. However, i'm sure this is wrong! If there's a loud bang a short distance behind you, how do you know it was behind you? The sound would reach both ears at the same time, so the source could be infront of you, or even above you!

We can all see, hear, touch, taste and smell.  Dolphins can use radar.  Pythons use infra-red.  Anything else?