> A 2x4 LEGO brick manufactured in 1958 will snap perfectly onto a brick molded this morning in Denmark, China, Hungary, Mexico, or the Czech Republic.

In the late 90ies, I regularly played with my uncle's old LEGOs from the late 60ies and early 70ies. They were stored in an unheated attic for 25 years. I remember that some of the old bricks didn't "snap" at all anymore to my newer bricks. They were either extremely difficult to stack onto a new brick, or didn't have any friction left.