Interlocking Pieces

Once upon a time my grandfather had handed me a cube that was made up of multiple interlocking blocks.  The pieces were slotted in such away that the puzzle would only release if the right combination of blocks were moved.  I found the cube very ingenious and I have been intrigued by similar puzzles ever since.  Life can often be puzzling, multiple interconnection locked together, the challenge is to remain intrigued and not give up.