Ditto for the fountain pen. For the past few months I've been trying to switch off the computer as much as possible and do as much writing as I can by hand. I can concentrate a lot better and I enjoy the physicality of handling a good pen and actual paper.
Lisp dialects are usually nice enough to write on paper. Because whitespace between list elements is never important in classic Lisp, you can break lines wherever it makes most sense visually to do so. Plus, the referential transparency means that you can write on loose sheets without any specific order (although many Lisp compilers do read top-to-bottom in practice).
ML and Haskell-like languages are also good, although you can usually forget writing the terms and just construct everything in types.
I've loved fountain pens and ink for years. Used an iPad with an Apple Pencil (which are great) for a couple of years, and then recently came back to fountain pens and pencils. I missed them so much!
What pens have you/others been using? I like the TWSBI 580.
I use a Lamy 2000 and find the shape, balance, and weight to be perfect.
Different inks can transform the writing experience; Aurora’s Black ink is very wet, and in my Lamy, writing with it is effortless.
I also enjoy writing with dip pens. The Sailor Hocoro (1) works with fountain- and dip-pen inks and has a smooth-writing steel nib. I use it when I want to write out some passage or quote in another color. India ink is the blackest black and I love it for that, while walnut ink is a pleasingly light sepia.
1: https://www.gouletpens.com/products/sailor-hocoro-dip-pen-se...
All through university and for several years afterwards I had an Online Vision Classic, which served me very well. Unfortunately I lost the first one at some point, and its replacement had various issues. So a couple of months ago I decided to go for a really good pen, and got an Otto Huth design 04. It looks great, lies comfortably in the hand and has an excellent nib.
If you want to try something wild: take a side project and do your programming on paper.
Type the code in and run it if you must. But go back and write in pen and ink.
It sounds weird. Programming languages have a lot of funky syntax. You’ll find the impulse to either find short-hand or else you will start structuring the program such that you can keep (parts of) it in your head.