I'm surprised no one has responded to this thread yet.
The Astral plane is where your Astral self/soul/ect projects onto what is called the Astral plane. It separates from your physical body and is capable of traveling onto this plane.
This plane allows you to do what you cannot on the Physical.
Having a wondrous mind is perfectly okay, and I can relate. I also have trouble concentrating. You have to make sure you either meditate before attempting Astral projection, because this allows you to clear that wonderful mind of yours.
There are guided meditations and Astral projection videos on YouTube, I find them extremely helpful. Use those (usually the longer, the better) and ween off from them once you've got the hang of it.