Sad story. As a side note: After years trying to catch my thoughts on a computer, I’ve came to realize that handwriting is much more effective tool for me. My thoughts start flowing once I have a pen in my hand. Now I have a series of diaries that I use with several people, my wife, myself, my late mum.
When you say "with", do you mean you write a letter & other person writes an answer letter in that same diary? E.g. with wife; does that means letters between you both in that diary?
Yes, that's what we do, but not on a daily basis. Usually, when I'm on a business trip, I either take the booklet with me or I leave it with her and she writes her down thoughts.
Thinking of it, we had something like that in high school, where (usually girls) would use a single book with her best friend back and forth. We called it "Briefbuch" (letter book) in German.
When I completed School & later College, our girl classmates had something called ScrapBook, where everybody will write in messages & good wishes for the owner of that book.
Years ago, I bought a cheap starter fountain pen, a journal, stamps, envelopes, and paper. Writing letters and journaling is definitely different than typing (the pace is different), and a fountain pen means I can write pages without the fatigue that comes from ballpoint pens.
I'm sitting here with that same pen and a tiny notebook for my thoughts in my pocket.
It's nice to look back and see what I was randomly thinking of on a given day, and go back and expand/elaborate or reflect on it.
For me it is the speed difference that makes handwriting so satisfying and good. I type faster then I think, writing however is slower. Handwriting gives me more time to consider the content and often leads to higher quality content.
Whether it be love letters or an important business message, handwriting it helps.