Combining two of my favorite hobbies 
I can't seem to identify that fountain pen, but it definitely doesn't look like a Kaweco.  What pen is it?  I am surprised how many people are involved in both communities, I recently traded my CI VP for some mech stuff on reddit.
That's a graphic on the top on the Kaweco case.  

  Unless this was a joke and I just wooshed.  

)  But yeah, there's so much overlap!  I think it's the mindset of wanting "the best" of a specific item, and obsessing and collecting to find that.  Same with headphones, etc - so much community overlap it seems.