Mental Gymnastics is a polite way to say that! But yeah, there is almost nothing I cannot do without some thinking and time...and NEVER make a DAX formula so complicated that you can't figure it out the next time you look at your code. While you can get very elaborate and sophisticated, if you have written a page long formula in DAX you probably should have used MDX, a Stored Procedure or different technology. Just because you CAN do it, doesn't mean you should or that it will be scalable later. In my experience, I find that far too often I come back to old DAX code and think, "Why the heck did I do all this!?!??!"