For the cool stuff, I'm thinking of picking a project/skill each week and devoting a full week to that, to see if I enjoy it and can get any mental traction. Becoming more proficient with pure C has been a lot of fun, so I'll definitely push forward on that. I have a couple of Pico-8 projects to work on. There's any number of opaque or classical technologies that I'd like to understand more deeply. I'll enter a game-jam, just to keep myself on a proper schedule with a proper deadline. There are a lot of books I want to read.
At some point though I'll need to collect my thoughts and start looking for the next thing. I have recruiters already knocking on my door, and the company will pay for 6 months of job agency assistance. But to tell the truth, I just can't see myself jumping back into software engineering as a full-time career so I don't yet know how best to utilize these resources. Sorting myself out is a critical goal for the coming months.
"What do I want to be when I grow up?" is almost as difficult to answer at 51 as it was at 18.