All right, the lucid dreaming work, but not what my friend persuaded me to do.
My friend said that i would do two simple things:

*Go to school.
*Kill everything and everyone.

Now here's the story:

I don't quite remember what happened first, but i remember saying something like

"When i open my eyes, there will be a door."

Then there was a green door, i said:

"When i go through it, i will come to my school."

I went through the door, came right out to school.
I summoned some guns, but they didn't have triggers.
I said i wanted triggers, and they appeared.
I jumped up in the air and started firing everywhere, at everyone, but it didn't work!
Nothing happened to anyone, then i summoned new guns.
They where round, and flat, so i threw them away, and summoned new:

Instead of that part where the bullets fly out of, there where huge spoons!
Those didn't work either, then i tried to just hit people everywhere, Kung-Fu style.
Nothing worked, nothing at all!

Later on, i woke up.

What have i learnt from this?
*You can only do what your subconcious wants.
*My body count is still 0.