The first part of the decision for me was knowing that I wanted to move out - which meant I never seriously considered any universities in Melbourne.
The next part was degrees - I wasn't super sure exactly what I wanted to do yet. I didn't really want to just do a science degree, but I also didn't want to do a marine biology degree because it felt too niche. I looked at going to UTAS, but although it does do marine bio stuff, it didn't really have any broader enviro science degrees. Looked at UNSW for a bit, but if I went there I would have just done science, and also sydney is expensive. Thought about queensland for a bit, but it's too hot and there are too many bogans :p
Sometime amongst all that I found out that ANU does flexible double degrees - so I could do science and enviro science (despite how important that was to me at the time, now that I've actually started it, i think i would have been totally okay with just doing a science degree haha).
I did an excessive amount of research on the various courses that I could do at ANU, looked up stuff about halls and extracurriculars etc. Decided to come up for the open day in 2017, and loved the vibe, and now here I am. The amount of nature close by definitely helped the decision too, so if you're considering moving out, remember to think about the area as a whole, not just the university itself.