The two systems that decide the trip. Borrow the shelter for trip one if a mate has a spare — then buy whichever one you actually reach for.
Darkness is the newest experience of a first campout. Light on your head, light at the table, and a charge banked for the phone.
Count water deliberately and keep every smell sealed. Possums and birds attend every campsite whether invited or not.
The Australian sun does not care that it is your first trip, and a storm can arrive between tea and bed. Dress for both.
Small, cheap lines that cause miserable weekends when missing. This group is why any checklist exists at all.