I've read it autosaves when changing scenes but it doesn't for me. What's wrong?

It's LBA1. I just left the garbage truck and quit the game but next time i started it up i was at the very beginning.

When you say "the beginning" do you mean inside the asylum or just outside?

See, the truck doesn't leave the area, it's still the same area so it won't save.

An edge of an area is something you can't scroll past. The whole screen will go black and you'll appear in a new area.

Sorry if it sound sonfusing, I hope someone else can explain better. Basically an "area" where it's saved is either one large outside area, or a inside a building.

It's one of the things that pisses off new players. They think, "Right, finally got out of that jail, time for a break", then do exactly what you did. If you'd just played on a little more then you would have hit a save point.

I'm not sure what clues I can suggest beyond what ZFR has said, my solution was to play for a while such that the impact of losing a bit of progress is not as much. Another good idea is that if you feel that you've made a lot of progress, and want to make sure it has saved, go to a place you know saved before.

Once your past the first couple of bits it's not a problem. Until the end, when you have to remember - you get sent right back to the start of the construction site, but most of the changes you've made have stayed in effect, so if you moved the barrier, it's still removed if you die in the fight when you're ascending the tower (which you probably will).

Well i am trying to kill that white/blue elephant jail from behind by sneaking in from a hidden door. It's impossible i die in one shot and then re-spawn from the very beginning of the game.

When the "elephant nurse", a.k.a. SuperGrob, attack you, you don't die and respawn. Instead you get knocked out and sent to the nearest prison (sometimes getting sent to prison can be useful).

Don't try attacking them. You'll only be able to kill them very late in the game.

In fact, in the first stage of the game on Citadel Island try and avoid combat as much as possible.