Good lord.

I care about you. I really do. A lot.
The thing is, I still don't think I fully understand you.
It is frustrating to me, because out of everyone I've ever met, you are the hardest to read. I need to read people to figure out what they're thinking before they say it, but apparently I can't do that with you. That's why I worry about you so much. Because I can't predict your actions in the slightest. Sometimes, you do things that even though I don't understand your motive, I still try. I know I have some kind of connection with you. You've said this yourself; that I'm the only one that understands the concepts. In this way, I'm honoured. Because when you put your mind to something that's worth it, it's so much easier to grasp. I just want you to know that you are my friend and I love you, and that I care about you very much. I'll always be here for you no matter what, whenever you need someone to listen. It is the least I can do to thank you for opening up to me, and explaining how the gears turn up there. It was an epiphany for me.
Thank you.