someone that does that... and I'll believe the Earth is round!
Shape of the Earth is not belief.
People saw stars, different ones at south and different at north.
People saw horizon expansion when you climb higher. And things behind horizon coming into view from higher spots.
People saw round shadow of the Earth on the Moon.
They measured the size of degrees of curvature. They measured arc minutes. One nautical mile was at first defined as one arc minute.
They measured the difference in circumferences around equator and around poles.
They measured a little bulge below equator, just a bit bigger than above.
Shape of the Earth is knowledge.
Flatties are trying to return it back to belief, and ignore or discredit the whole history of geometry, geography,
geodesy, geology, astronomy, navigation, meteorology, ballistic, astronautic and rocketry, photography, physics, ...
They want you to "use your own head" in the way they tell you.