When I need to write something, and I have a computer, and something is inconvenient, I can quickly (well, within minutes, maybe 30 of them) alter it to my liking, and return to writing.

When I only have a pen and paper (which I used extensively for writing at school), many things may be inconvenient, but there's no way to fix it. This may turn into a source of a low-key stress, and interfere with my writing much more than tweaking a computer would.

I use Emacs, an ultimate tweaker's tool, for writing every day. Last time I had to tweak something in it was a few weeks ago, and it took maybe 2-3 minutes. It's a small price to pay for a tool that just does what you need, when you need it, with zero mental load, and zero frustration.

For my two main uses pen and paper has two opposite effects. For creative writing it is freeing because it isn’t the last stop but I don’t have to worry about format or placement or anything. I can just go. Typing has a sort of “technical” feel for me, probably due to code, email, and to some degree comments.

For notes during study pen and paper are constraining and force me to organize the thoughts in my mind first and then commit them. Mistakes needing to be corrected here is good: It reminds me what I misunderstood.

But, like the sibling poster, the writing goes onto the computer for later editing.