There's a trick to it. I was reading Ken Iverson's Notation as a Tool of Thought paper (look it up, it's worth a read) which is basically a whistlestop introduction to APL. I realised that it's very difficult (for me) to reason about when I read it left to right, but it's almost trivial read right to left.
That's right, it's a language that makes more sense backwards than it does forwards.
I heard somebody describe APL as associating "left of right", rather than "left to right", and it suddenly made sense. Reading it right to left is like reading it from the inside outward.
That's right, it's a language that makes more sense backwards than it does forwards.