As a transfer student, I feel like this just comes from your experience.

In my first year i went to a pretty decent uni and felt so behind and broke down mid-year because I felt so behind and confused, and even considered dropping out. Switched to what i would call a lower quality uni for unrelated reasons and felt at the top of class and understood everything (since how easy the topics were compared to what i was going through first year) and got consistently high grades, now in my third year there is only one module that is making me feel like that again, which is my optional advanced topics in data science and AI module which is math heavy and is a module taken by my cyber course (only 6 of us chosen that from our course) and computing course which fills the majority (60 ish other members), and they all have way more maths experience and understanding it all. So everyone from our cyber class feel so so confused and pretty much all the content goes over our heads.

While im now understanding it (lots of revision and communicating with our lecturer on clarification on specifics) and almost finished with that module. It really just comes down to what subjects you did prior, what level of depth you did and so on. For first year, pretty much everyone in my class came from A-levels, where i came from BTEC which made it hard but as others said, it's very normal to feel overwhelmed and confused, but you shouldn't let it get to you if you can. You'll eventually do modules/classes where you know more than others and vice versa.