Sure, it probably makes sense to someone who actually programs, but it seems counter-intuitive to me.
From the Game Maker Manual, and I quote:
Room start: This event happens for all instances initially in a room when the room starts. It happens after the creation events.
Now, when you phrase it that way -- "Room Start" -- it seems much more logical that it is processed after the object creation events. However, elsewhere in another, very important place in GM, it's called a room "Creation code". Logically, the room would be created before the objects put inside of it, wouldn't it? I mean, aside from God creating light without celestial bodies to produce the light, the whole of the universe was created before the plants, animals and humans were put in it. You don't make an omelet without first taking out a skillet or frying pan. You don't make perfume without first making a vial to mix the chemicals in.
But apparently you can make objects without first making a room that they're made in. This pretty much renders the Room Start event nearly useless. This caused me so many headaches, trying to set unique values for instances.
And oh the joys of reading the manual! I then stumbled upon this line of scripture as well:
In the pop-up menu when you right click on an instance with the <Ctrl> key you can now indicate some creation code for the specific instance. This code is executed when the room is started, just before the creation event of the instance is executed. This is very useful to e.g. set certain parameters that are specific to the instance.
...
*chucks his laptop against the wall*
Edit: Anyone else notice in that last quote it says the room is started before object creation? What the hell, Mark?!