Note-taking is a habit you often need to train. I still occasionally pull out my phone to jot something down - a leftover habit from a time when I was heading in the opposite direction I am now. This means that for some people, it’s difficult. Finding what mental blocks you have for it, the why you didn’t reach for your notebook that time, or the what that makes you leave it at home instead of having it at the ready, and then considering whether those reflect your values or not, can often help more than just your note-taking. In fact, realizations of that type are perfect for jotting down in a … notebook!
As others have mentioned, bullet journaling, GTD based practices, or other self-organization techniques are great ways to often begin addressing several issues at once: personal coherency and rhythm, enhancing mental focus and presence, efficiently organizing your time and effort intentionally towards your goals (or figuring out your goals from your values, if you’re not at that stage yet - which is entirely valid too), and of course just the value in having one place to put some of the chaos so your brain can let go.
One of the things I learned early on about note-taking in any form is that if I don’t write it down, the to-do and don’t-forget lists in my head get significant and I go around always with a heavy mind, clouded and cluttered and anxious that I’ve forgotten something. The more I transfer out of my brain and into organization systems around me (and then build habits to utilize those systems!) the clearer and more peaceful my mind becomes, and that helps it do more useful work like deeper thinking, handling difficult situations with more grace and reserve, or just being free to play and dream and imagine without feeling tired and weighed down. Field Notes for me are almost perfect. I still need to be able to effectively utilize a paper planner - the automatic reminders built into my phone are a gods-send for me right now - but that’s not an urgent transition. It’s one I’m sure will come with time and a more personally structured lifestyle, the organization and creation of which are my main goals right now.