Say you own a company which has a profit of 10.000 Euros on average the past 3 years. Before you can leave Germany you will have to pay taxes based on 137.500 Euros.
One important note: this 13.75x valuation is a worse case scenario if you fail to supply your own. There are many ways to reduce or avoid this tax.
It's awfully convenient that someone else went through it and started a website just for that topic. Funnily enough, his website was inspired by mine, and this guide was inspired by his post on exit taxation.
It's a far better resource on the topic: https://wegzugsteuer.info/
As a USAmerican though, I see it as more general—a statement about how modern, "1st-world" civilization has become so god-damned complicated.
I catch myself (especially since I have kids) realizing how difficult it is to navigate some aspect of modern life (for example, various payment methods—credit cards). A kind of mantra that always rises in my thoughts is, "No one would ever have designed the system to work like this."
Somehow, independent actors, independent reasons, likely the ability to make it this complex has indeed made it this complex.
It's no surprise then that just functioning in this modern society induces a level of background anxiety. Pretty much the opposite of "touching grass".
What got me to work on this was a related post on the German exit tax not too long ago: https://news.ycombinator.com/item?id=44828158
I don't gain anything from promoting my free, hyperlocal content here, but I love to talk about my work and the discussion here is unfailingly interesting.
The closest thing I've seen is guides for changing your name in various USA states from the trans community; some of the processes are quite arduous (NJ for example has about 15 steps, most of which are manual separate errands with separate waiting periods...)
The biggest problem is that the government often describes bureaucracy in terms of what they need from you, not how their services fit in your journey. It feels like we are serving the bureaucracy and not the other way around.