Greed is bad in life and chess as I learned the hard way on a live chess.com game. The game I played was about equal until move 14 when I made the terrible decison to play f6. This allows white to gain control of all the active squares, leaving black 2 pawns up but checkmated. I was amazed at the tremendous attack someone could gain from a lack of development, even with no queens on the board.
A valueable lesson to all, never take material and give the opponent complete control over the board. Its not worth it!