And well, I totally understand it'd my loss if I simply got 50s in my first year but what if I were to put out a heap of time in my second year recovering my bases and filling up certain gaps?
To be honest with you, engineering/science is hard enough as it is even when you do have a good basis, and did well in first year. Why put yourself at a disadvantage already?
It's happened to me before. I didn't understand half the things we did in GMB, methods, physics and chemistry last year (didn't do much homework, I played footy/tennis most weekday nights then spent the rest of the night on Facebook..) I also nearly failed unit 2 chemistry and GMB as well, but I studied heaps over the summer holidays, stopped playing sport outside of school this year and pulled my head in.
VCE/school and Uni are different, yeah in school you might be able to slack off and then put hard work in and catch up. But once you get to uni you're putting that hard work in just to keep up with the course, you need to work your ass off just to be average. You will need these foundations for second year, and you won't have time to catch up on them in second year if you slack off in first. You hardly have enough time to get through the second year content.
Uni isn't easy, it's not VCE anymore, the amount of content and difficulty of content is a hell of a lot harder than VCE. You need to put the hard work in to get anywhere, and it just gets harder later on.
As other people have said, you get a really large holidays after VCE, it's long enough that you eventually get bored and want to get back into work. I don't see why you would purposely make it harder for yourself in the future (and which could result in you paying more as well).
If you do decide to do this, you'll probably get the wake up call after your results in first semester.