Background: I have done 5 years of university study, two degrees (1 bachelor, 1 master) at two different unis (La Trobe and Monash) in IT and Education/Teaching. I have been on both sides of the uni teaching/learning - as a student, and as a tutor/teacher/demonstrator.
10. I did great in HS, that means I'll do good in uni
God, this. SO MUCH.
I was a tutor for a first year programming subject and the amount of cocky 1st year students who thought because they got awards/dux/etc that they'd be automatically amazing. Mmm.. two different universes. Cockiness usually results in downfall somewhere, so get as many friends as possible and use/abuse your tutors/teaching staff. Don't try and object to what the tutor/lecturer is saying (if you disagree there are ways to go about it) and
definitely don't give off the "i know more than you" vibe.. never ends well.
You essentially start from scratch when you move from HS to uni. No one cares if you received a 40 ATAR or a 99.95 ATAR.
5. You'll make all your friends during week 1.
It took me until the 2nd last week of the first semester to start connecting with people. IT was a very.. unsociable discipline where people kept to themselves (that's quite interesting because the industry is the complete opposite). Anyway, it went on from there.
8. I don't have any friends from my HS, it'll be lonely.
I did my course without knowing anyone (in fact, I don't think anyone I knew went to uni from HS). You need to put yourself out there. People will come up and talk to you or engage in short conversation. Be receptive. Don't be a snob. If you don't engage with other students even during tutorials/labs/pracs etc, it won't happen. You have to be willing to make the effort.
6. Clubbing is an essential part of student life.
False. Went the entire 5 years without clubbing/going to any of those wild events. Wasn't really my thing.
- Group work can be great, but can also be a massive flop. It's usually the latter.
Most of the time. Every experience i've had over my uni life has been terrible. Try avoid them if you can.
- A lot of textbooks are expensive and unnecessary, so wait until you're a few weeks into semester to see whether you actually need to buy the textbook.
This. Majority of lecture slides/notes are written from the prescribed text.. so ensure that is is absolutely necessary before you go forking out $$$ which you could be using for something more useful.. like.. subway daily.

A few of my own now:
"All tutors are voluntarily here and want to help me succeed"False. Quite a number of them are there because they are doing a PhD with the subject/unit coordinator. Some do it just for the money (teaching associates/tutors get paid very nicely.. so make sure you use and abuse). Some of them are
really good and genuinely give a shit, but majority don't.
"Lecturers primary role is to lecture"False in majority of cases. Lecturers primary role is to contribute to research efforts. For many, lecturing students like yourself is a secondary gig.
"All tutors/lab demonstrators are PhD/master candidates"False again. I was a tutor/lab demonstrator in computer science as a 3rd year undergraduate. It's hit and miss - some are good, some are absolutely terrible. You'll know very quickly what one they are.
"I am going to drive to uni, there will be plenty of car parks"Don't. Unless you intend on arriving at 7am. Forget it if you plan on attending later. Use public transport - save yourself the hassle, time and petrol money.
"The uni cares about me, i'm not just a number"Faaaaalse. You are actually a number. In some units, there are 700+ students enrolled in it. Do you really think they try and individualise programs for you? It's a pre-defined sequence of lessons.
Voluntary programs/assistanceIf a unit/person offers a voluntary program (e.g. a maths assistance program) and you feel like it would benefit you, go to it. As stated, you are essentially on your own and there is absolutely
no hand holding. When I did my undergrad, the uni offered a maths support program which assisted those who needed that extra bit of help with their math on a weekly basis for 1 hour. Not many turned up, but I thought it was an amazing program.
"I won't hand in weekly tasks/assessments on time, i'll just get given an extension like in high school"It is nothing like high school. If you don't hand something in and don't have a bloody good reason for it, you'll get zero for it. They won't hold your hand and tell you everything is going to be ok. If you need an extension, you are required to request it before the due date and have a good reason.
Pass ratesIn majority of units at uni, the pass mark is 50 overall. However, if you get something like 46-47, it is very unlikely that they will bump it up to a 50. It's really important that you put effort into each and every unit you do at university. Depending on the unit, failure usually means that you have to a) repeat it and b) pay the financial cost again. The other issue here is that with units, they are usually pre-requisites for future units as well. I'm sure you can guess what happens here... fail the prereq means you won't be able to do the future unit, which means that you'll be behind even more.
TransfersWhile it is common to transfer from one degree to another, you need to be aware of the fact that transferring to another course has its disadvantages. If it's a completely different discipline, you may have to start again (and of course, this means more of a financial burden). Before you transfer or change your course, make sure that you can claim as much advanced standing/credit as possible (and be aware of it
before you transfer).
All I can think of.