If you guessed me, you are correct. For those who don’t know, the earth’s axis isn’t always tilted at the exact same angle. Over time the tilt has changed ever so slightly and rotates a bit like a top, an act known as precession. The earth’s axis returns to the same spot once ever 26,000 years or so. As a result, the earth’s relation to the Sun changes, which affects when the Sun is in certain constellations on the ecliptic. We won’t notice it much in our lifetime, but it becomes noticeable over thousands of years. This is something everyone learns in a basic astronomy course, along with the presence of a thirteen previously unloved ecliptic constellation called Ophiuchus. My professor for that class introduced the concept the class before we learned it as “why astrology is wrong”.
Enter astrology. The signs and dates you know and choose your reactions to as appropriate were chosen thousands of years ago. The earth has made a significant chunk of its precession trip since then, and as a result when the Sun is in a given constellation has also changed. Someone pointed this out, it made the Internet, and chaos ensued as some people discovered that their signs have changed. They complained that their new sign didn’t describe them at all, that their old sign was much better, and that changing the zodiac was silly in the first place. Funny, I don’t see a single person praising the change, but those people probably know their astronomy.
As for me, I’m supposedly a Sagittarius now, whatever that means. I’ll continue living my life in ignorance.