That One Piece of.....

-chicken.
-pork.
-beef.

You fill in the blank. Have you noticed how when you have to brown small pieces of meat (ie. diced chicken) in a pot, there's always that one stubborn piece that won't flip over? You can tweak and tork and swirl and toss all you want, but there's that one piece that refuses to turn its topside over. Why is that?