Perhaps I'm
$\pi$
My life is internationally famous. In fact, infamous too in a way.
$\pi$ is known to students of mathematics around the world.
Maybe called infamous due to claims that approximations like $ 3, \frac{22}{7}$ are actually equal to $\pi$, or
due to where it was discovered involving at least Egypt, Mesopotamia, Greece, China and India.
Many call me illogical or unreasonable.
$\pi$ is an irrational number (not a fraction of whole numbers) - proved by Johann Lambert in 1761.
My main rival is from Greece, unfortunately, me too. He tries to turn away from me always.
$\tau = 2\pi$ ( tau also a Greek letter) has been promoted as more fundamental: The Tau Manifesto.
A rotation of $\pi$ is a half-turn of a circle, $\tau$ is a full-turn, so in rotation they are opposite directions.
I am surreptitiously in love with an English girl. But it is hard for us to stay together. People try to separate us.
The English girl may be e, and together these make pie, which people like to slice up and eat.
Amidst all these hardships, I never stop my life journey.
When written as a decimal $\pi = 3.14 159 26535 8979... $ and this continues ad infinitum.