From what I understand from this write
we mostly want what we can't have.
And if we do it brings us nothing but grief.
nice piece Thomas

What you had once
You want the most
I believed this
And really wanted you close

^In the beginning you were still in love, still wanted her and was hopeful everything would work out.

But in the end
My mind gave me a lecture
Dissected in close detail
Your crooked structure

^You listened to your mind instead of your heart, which is really hard to do. You dissected every part of your relationship and realized that it wasn't best for you.

So don't call me insane
For not wanting you back
Cause like a bad refrain
It would get stuck in my head

^She is calling you crazy for not wanting her, she is hurt and with hurt the name calling happens. You don't want to have her stuck in your head anymore.

I just want to fornicate
And release my inner lust
I don't want to replicate
The failed relationship we had

^You just want the physical part. You want to turn off that part of your brain that feels love and just not worry about the failed attempt of a relationship.

No longer am I willing
To risk my fragile emotions
To push my sanity
Back through turbulent motions

^You are done - tired of putting your heart through chaos, tired of breaking down - feeling crazy.

Great piece with lots of emotion and many people can relate to this.