A few years ago, I used to commute by car from Nottingham to Wolverhampton/Birmingham.
I was finding more and more that I was switching to autopilot because my mind was wandering to work matters (what am I going to do today, that sort of thing) as well as dwelling on things at home.
After a while, this started to worry me as well - especially when I was finding half-smoked cigs in my hand that I didn't even notice that I'd lit-up. Got me so worried that I changed job from a 70-mile each way commute to a five/ten mile one.
What helped me then, though, as it does now on the bike, is doing a mental commentary on the ride - how I'm riding, hazards, weather/road conditions, where to filter (or not), that sort of thing. Tends to keep the mind focussed and stops the autpilot.
Dreaming of life in a modern secular democracy. If you find one, please let me know. Apart from France, that is, because it's full of cheese