If you have access to the room with the writing on the wall and the "don't let ..."-note, you should have a crowbar already which means you're not doing anything wrong or are missing something. You just went a different path. (So you're technically in section 2 now.) There is no "standard" way to play the game, it's changing by your choices, where you go etc. So you can't see everything in just one playthrough. I guess next you'll have some puzzle work to do. I hope I was able to clear things up for you a little bit. :-)