Good call, that's why I refuse to learn people's names. It's just a stupid label I might get wrong sometimes and divides people, so why would I bother learning someone's name?

(I'm being sarcastic, labels and pronouns are not this complex, just call people what they ask to be called)

Gender isn't sexuality.

The prefixes cis- and trans- are rooted in Latin, and is commonly used in chemistry to describe the geometry of a molecule. The terms mean "this side of" and "opposite side of" respectively. It's the same trans you see in "transatlantic", as in "far side of the atlantic ocean", and indeed the word "cisatlantic" is also in the dictionary.

So that's precisely what trans-and-cisgender means. A cisgender person is someone who identifies "on the same side" of the gender they were assigned at birth, ergo they identify as their birthgender.

They're not terms you need to identify with or use. They're simply terms used to make a clear distinction in conversation where such a distinction is necessary.

Awe, poor you having to learn new words.