There are a lot of things in various programming languages which are hard to remember, but k and array languages have such a small surface area, not being able to remember it while working with it daily amounts to learned helplessness.

(source: mostly amateur k programmer, also worked with it in a bank, find it vastly easier to read/write/remember than most mainstream languages)

Not that it's impossible to remember, bit it's definitely contrary to most traditional use of the symbols employed in it, though not without logic. My favorite is the functions from io package, called 0, 1, and 2 (yes, numbers) which handle interaction with stdin, stdout, and stderr respectively. In dyadic form they at least have a colon, but in monadic form they look like plain numbers: 1 "Hello world".

I suspect that to study k (and use kdb) efficiently, you need to actively forget what you knew about the syntax of other languages, and study k as a language from Mars that happens to map to ASCII characters somehow.

It is really easy to remember; it is so small that remembering is the least of the issue. The rest is just using it a lot; I find it readable and nice to work with. Unlike other some other languages we get shoved down your throats.