My car had been out in the school lot all day, and its windshield was crack free when I drove it home and parked it in my heated garage. The next morning, there was a single line in the middle of the windshield. My theory is that it had been weakened due to gravel strikes which had not left a mark, but the temperature difference was enough strain to leave its mark.
Over the years, the line (which was too large for a quick fix from the beginning) slowly grew, bending a bit at a couple of points. It was something that was easy to put off. I finally decided to get the windshield replaced, and did so today.
Driving home, it felt like something was missing. That crack had been in my view for so long that I almost missed having it there. Almost. I also revelled in the amazingly unobstructed view that I now had when driving home. Although it may take a little while to get used to, the crack was a distraction, and I am glad to no longer be impeded by it.
I cannot help but feel that there's an analogy here, but I think I will let it pass.