What you linked is very different. It’s something you write down but are expected to still remember later. If this helps you with your grocery list, then yes this is good, but if instead of actually using your memory you look at the list, that’s what’s bad.
In a test at school for example, handwritten notes does help memory, since you’re still expected to use your brain later to remember it, as opposed to reading the notes.
Note that while I say it’s “bad”, it’s really just one factor among many. Just like everyone knows sugar is bad yet everyone consumes it to some extent. But the more of those “bad” things you avoid, the less likely you are to suffer from memory issues later.
Agent: I need your account number
Me: I have no fucking idea. Can you find it from my phone number?
Agent: Sure, no problem
Me: Then why the fuck….?
Relevant Chris&Jack