Now I finally understand how they've stayed in shape all these years...
https://www.redbubble.com/i/art-board-print/warren-buffett-charlie-munger-by-magnacartan/55781187.8DB3C
Side note: Of all places, I found out their secret via Redbubble (ASX:RBL) which is a user-generated content marketplace with a wide range of print-on-demand items like home decor, clothing, and all kinds of accessories. It happens to be down -80% in recent months like many other tech names but is actually cheap on an absolute basis of ~1/3 of GMV. Fascinating business going through major long-term operational improvements after the new CEO came in, but market has been mostly focused on short-term comparisons with peak-COVID sales (which they benefited from over $30m of mask sales.) This is not a stock write-up but it seems like the long-tail of niche interests (like the COBF msg board community here) is a large addressable market that most retailers / e-commerce players have neglected.