Actually I do maintenance for old watches (most of them "Made in GDR") to keep them running. Yes, it is fascinating. It also offers an abundance of opportunities to crawl around on the floor and practice the proper use of swear words while searching for small parts that made it to the floor .
I used to make some jewellery too. It comes in very handy when you need a gift for your significant other and only have some sterling silver wire and solder. I created a small collection of chainmail themed items.