Technically speaking I believe fresh eggs are strong tasting because part of the egg, the air cell, is still intact. Over time the air cell breaks down and air from outside the egg enters and the egg loses much of it's flavor. Liken it to freshly roasted and ground coffee compared to a 3 month old can of Folgers that's been sitting in your cupboard. The fresh and strong flavors in the free range or freshly laid eggs are quite rich... Check out this site for more info:
http://www.aeb.org/LearnMore/EggFacts.htm
Basic Egg Facts
Air Cell
The empty space between the white and shell at the large end of the egg.
When an egg is first laid, it is warm. As it cools, the contents contract and the inner shell membrane separates from the outer shell membrane to form the air cell.
The candler uses the size of the air cell as one basis for determining grade. In Grade AA eggs, the air cell may not exceed 1/8-inch in depth and is about the size of a dime. The air cell of Grade A eggs may exceed 3/16-inch in depth. For Grade B eggs, there is no limit on air cell size.
As the egg ages, moisture and carbon dioxide leave through the pores of the shell, air enters to replace them and the air cell becomes larger.
http://www.aeb.org/LearnMore/EggFacts.htm
Basic Egg Facts
Air Cell
The empty space between the white and shell at the large end of the egg.
When an egg is first laid, it is warm. As it cools, the contents contract and the inner shell membrane separates from the outer shell membrane to form the air cell.
The candler uses the size of the air cell as one basis for determining grade. In Grade AA eggs, the air cell may not exceed 1/8-inch in depth and is about the size of a dime. The air cell of Grade A eggs may exceed 3/16-inch in depth. For Grade B eggs, there is no limit on air cell size.
As the egg ages, moisture and carbon dioxide leave through the pores of the shell, air enters to replace them and the air cell becomes larger.