Is it a sign of me being basically 'too dumb' if I still need to ask questions after almost 2 years?
Not at all. But it sounds like you're asking the wrong questions.
I asked an experienced coworker if he could give me a quick introduction.
That's beyond vague, and sounds like you haven't even tried to figure it out.
If you asked me to give you a "...
often task descriptions are vague or straight up incorrect, and I am
expected to remember verbal discussions that directly contradict the
story descriptions. I am bad at remembering verbal things, which is
why I rely on notes and written story descriptions a lot, but they are
often unreliable as changes in requirements are not documented. I feel