Farmers' Museum in Cooperstown NY, I saw a demonstration of dried flax stalks being turned into linen fiber, by hand. It gave me insight into linen fabric I would never have had otherwise.
(I'm dying to get back to the museum... if you ever have the chance, be sure to check it out.)
The tall stalks go through a five-step process to prepare it for spinnning, delightfully called rippling, retting, scutching, grassing, and hackling. First, they are combed to remove seeds and leaves, then soaked, then dried. Then they are beaten, and the stalks separate out into long individual strands, and then they are put through a fine comb to create yarns for spinning.
The resulting yarns and eventual fabrics contain all the irregularities of the original plant stalk, which is why linen has a "memory" and does not retain a pressing.
Linen fiber is one of the strongest, which is why it can be combed into extremely slender yarns for fine linen like lace, bedding, and table linens. Linen also is lint free which makes it perfect for kitchen dishtowels.
Seeing the linen yarn appear before my eyes at the demonstration at the Farmers' Museum was one of those "aha!" moments for me. It was like magic, and I don't look at fabric in the same way since.