I dont know if it's an ADHD thing but the type of notepad and size makes such a difference to me.
I began journalling through poetry, then morning pages so I got used to A4, but A4 felt too big to carry around. I'm also very disorganised and would have creative writing, word vomit, notes, and to do lists all over the place. Then I found a B5 journal with numbered pages which was perfect, I could get lost in journalling and organise with page numbers later. But I was travelling and wanted something smaller, I got swept up by the traveller's notebook hype. I bought standard, passport, and found both irksome. A6 and B6 is nice, but I couldn't stream of consciousness the same way. I also found it difficult to "bond" with my journal because it was so modular.
Various set-ups, and finding a couple gorgeous journals later, which are too nice to "ruin", and some others which have lines too wide apart, or too dark, I'm going back to the trusty numbered B5 with perfectly faint 7mm lines. Finally can get back into journalling, and hopefully creative writing, in a way that feels effortless.
It took me ages to do this because I couldn't fathom how something so trivial would matter but alas
If it ain't broke, don't fix it 🥲