Some of it is easy to learn.. like drag, sis, etc. But there a few that you'd definitely need an explanation for because you don't see them around the Internet much, if at all. Tho I wasn't really confused about much and started using them quickly.

I didn't understand the obsession with random letters eg:
dddddd
fffffff
k
nnnnn

No.

Don't come for the flawless nnnnn

At first I had a hard time with the smiles and gifs. Didn't know when and how to use them.

Not really actually.

This. I learned most of them because of lurking

Yes. I lurked but I never paid attention to it.

Alot of it still feels forced into my vocabulary.

Mess I still don't know where to get them. I just go into old threads and reuse worn out gifs

That's what I used to do

Yea, I didn't know what troll meant.

I still don't know what kii is or the nnnn; thing but I actually use ATRL lingo in my daily life now, it's becoming a problem
I always say drag, scalp, "not ______", iconic, slay etc...

It was always funny to me so i was eager to learn it. Never really confused me

I lurked for ages so upon registration the words/smilies codes were like a second language

I was confused about the kiii and nnnnn;;;. So dumb

And I'm still confused on how male posters call each other "sis". I have a dick, don't call me sis