Save system in Amnesia

[ShnitzelKiller]

So I played the demo to the water monster part with my lantern oil full, and of course I died, not knowing at first how to avoid it. I spent quite a bit of time jumping frantically and running around and using up lantern oil, and one thing I noticed when I restarted the level was that the lantern hadn't restored. Is this a punishment system in place to discourage people from attempting trial and error through dying a lot? Or is it just a bug?