I was motivated to stop because I was a bit too successful: I had become the 2nd ranked great power in the game by accident. The Holy Roman Empire had simply chosen to elect me as their emperor, although I wasn't an elector, and had done absolutely nothing to curry the favors of the electors. That felt weird to me, ahistorical, and not actually that much fun. The other success that was ahistorical was that I had already discovered North America, and had colony growing in Maine. With England nowhere in sight, mostly because the Hundred Years' War had dragged on a bit over a century, it seemed that I was the only colonial power in North America at that point.

The other reason that I didn't want to play on was that I do like to check on YouTube and Twitch what content creators are doing to get some advice. But I'm not the only one for who the first century took so long, and thus content for the Age of Discovery and beyond is actually hard to find. Florryworry has a Twitch stream on Holland, but that is because he plays extremely fast, and thus explains a lot less. What I did learn from him was that there is a sort of exploit, where you do take locations you don't actually want in peace negotiations, and then sell them for thousands of ducats to the great powers. That boost your own economy and hobbles the economy of the great power, as these locations aren't actually worth that much to them.

So I started a second game now, with ironman and achievements enabled, playing Mecklenburg. That country has a nice location right next to the Lübeck market center, and a lot of smaller neighbors you can gobble up quickly at the start of the game to grow into a duchy. I won't do any exploration and colonization in this run, and hope that I don't get elected emperor of the HRE again. I just want to play a mid-sized country through 5 centuries.