When most of us learned chess, we were first taught to grab material and have a material advantage. This is not that bad, but playing positonally is usually better. Take a look at the starting position of the example below. You'll quickly notice that black has a material advantage,  but is in a terrible position. Go ahead and solve the puzzle, and then check the move list.

nothing wrong with your solution.  But, k-e4 is another way of going about it.  then the king can stop the pawn if need be

Is a clear example of zugzwang, dominanation by a pawn.