Was hoping for the Celebrity achievement (get 15k prestige) on my old man Fylkir/Emperor, who was heading into his 70's. Managed to get it at age 72, and then I was hoping for a better heir (ultimogeniture, youngest male child inherits) though thought it unlikely given my guy's wife was old, and I didn't want to get any concubines.
Forgot about his lover though. He was 76, got a little pop-up saying I have a bastard son from this 27 year old he gave a good tumble to 9 years previously. After a little thought, decided the reputation hit with the entirety of his immediate family would be worth legitimising him, so I did.
He died a few months later, and I get to play as my first 0 years old character
Further ownage occurred immediately thereafter when Scotland decided they wanted to take advantage of the Empire being in flux, and to declare a Holy War for Dunbar, while I was still mopping up some Lithuanians. Sorted them out, but took a great hit to the number of troops I could field, and then some of my vassals decided they no longer wanted to be part of the Scandinavian Empire, so they revolted. Despite having slightly fewer troops than they did, managed to make them surrender after 4 years of hard battle, and imprisoned 9 of the bastards.