I cringed at the topic "as a former NASA Astrometrist" but if you look up... in the Northern Hemisphere, we have Polaris (the North Star) relatively stationary in the sky. Just use your phone with one of those sky apps. Now, get on a plane and go to Australia... Polaris drops below the horizon and isn’t visible at all.
Meanwhile, now that you are in Australia, you can see the Southern Cross (Crux). No amount of weird “perspective” or “light bending” on a supposedly flat plane can explain why completely different stars are visible as you change hemispheres.
For the average Joe, Earth should be considered a perfect sphere:
Equatorial Diameter: About 12,756 km
Polar Diameter (North to South Pole): About 12,714 km
That’s a difference of roughly 42 km. It may not sound like a lot on a planetary scale, but it’s enough to show up in measurements and in Earth’s rotation characteristics. But that's only for scientist. For most people 42 km in nothing compared to almost 13,000. The more you know...