Six Breaths Per Minute
I was surprised the first time I heard that the optimal number of breaths per minute for a human is about six.
Try it: sit down somewhere comfortable and try to take six breaths (in and out is one breath). Make each one last about 10 seconds. No need to time it perfectly.
When I first tried this activity, I pictured my breath going up a flight of stairs and back down. Or perhaps taking an elevator to the top floor, and then back down to the basement.
Not a journey, but exercise for the mind.