This is pretty much how I feel every time delving into FFTs. Like, I get the concept, but something in my brain just shuts off when it comes to actually trying to grok it. I do however very much appreciate those that have created software where I just provide --input and they handle the rest.

I also have trouble wrapping my head around all of this, and complex numbers, for that matter. Never mind that I'm employing this stuff all the time in GNU Radio.