Writing for brain health

I've reached a certain age where I'm starting to pay more attention to keeping body and brain healthy as I go into my so-called retirement years.  And I think a good way to keep the brain working well is to plan and write and novel.

A novel is a series of challenges and puzzles for the main character that have to be solved.  And that means the writer has to solve them too.  In my novel Combined Cogrnition I have several crimes.  They weren't all committed by the same person, and in early drafts of the book I didn't know why some of them had been committed, and I needed to find out why.

Part of the challenge of figuring that out meant creating motivations for murder.  Why did that person want to blow up a big chunk of an orbital shipyard?  I wanted it to be a big explosion to create a strong  Supreme Ordeal for my story, but that a meant the motivation needed to be bigger than one individual pursuing a petty agenda.

What I came up with was a historic war between Humans and the Oriellish.  And the centenary of its ending is approaching.  Oriellish have long memories, and bear grudges for a long time, so one of them is going to use the upcoming anniversary as an excuse to attack the shipyard.

I've got to the stage in my writing where I plan my novels before I start writing them.  And I mean a detailed plan, one that works out where each character is at each moment, and what they're doing.  I sometimes find working this out a struggle, usually because I haven't got enough exciting bits in the story and need to create more danger for my characters.  Working out the traps and  cliffhangers can sometimes be a strenuous brain workout.

In the novel  I'm writing now, Renaissance, I wanted an AI to defend itself using what is in effect a recycling facility.  It's one of those places with a big sorting belt, and chutes that take sorted materials away to be reprocessed.  We know from real life that such machinery can be dangerous.  It's easy to rip off an arm in a fast-moving belt.  But how could I use it to kill people?  People who weren't willingly going to go near that belt and put themselves deliberately into harm.

Working that out was a good puzzle.  And I have the added benefit of knowing that challenging my brain to do that was helping it to stay healthy.  I think that's a pretty good reason for writing.