I hope you're being sarcastic there, "ipt is sOooo hard".
I hope so
Because if you were being serious, there must be something amiss.
There aren't that many things to remember, as one idea generally links in with another. So you'd talk about data validation, which then links onto data verification, which can link in with error correction methods, which links with parity, then with synchronous transmission, to transmission methods (wireless/wired), to transmission mediums, to hardware, to software, and so on and so fourth.
Assuming you're doing the preliminary course now, you don't have to remember everything that you've learnt in the preliminary, besides a few basic things (project/group work towards the end of the course).
If you're sitting for the HSC next year, then you might have a few more things to learn, but overall, it shouldn't be too difficult for you to grasp the concepts and to apply them in specific examples/scenarios.
Good luck with it