Why do I have bendy, twisty hair strands?

Every now and then, I find a hair strand that has kinks in it and it curves, bends, and/or twists in random directions. Sometimes they are shaped like letters like J L S C and even a question mark (?)... Like a slightly used, straightened out twisty tie for garbage bags.

For example, a hair strand will start of looking normal for a centimeter, then has a sharp bend 20 degrees, then curves back, then twists, then bends the other direction 40 degrees... All within a 1-2 inch hair strand.

Most of my hair is considered "normal" but it is extremely frustrating when styling my hair because the bendy hair strands stick out from any style I try to achieve and makes my hair look messy and not groomed.