Have been collecting fountain pens for a good few years now (not quickly, mind, but steadily).

I annecdotally find that i remember things much more clearly when I write with them, particularly when I use varying ink colours. And when I flick back through notes seeing the colour for a topic makes it much easier to skim and recall knowledge.

To add to tge recommendation list, the Muji fountain pen is perhaps the most enjoyable pen I have, including all of my (embarrassingly) expensive pens.