When there are more years behind than ahead, contemplative stewing and meditative mulling is the operative daily mode. That process clicks into place and idles away unaided. It's sneaky, this mental program, having automatically installed itself at some point or other, perhaps when a certain number of breaths has been taken, or something similar.
It's very much like a perpetual motion machine you never knew you had -- one that kicks into gear suddenly and without warning, slipping any and all restraints, unexpectedly puttering and pottering around all by itself. This latent skill is an intriguing discovery at any age, but especially when you think you've already got yourself fairly well figured out. By now, you've sort of thought of yourself as pretty well knowing how to be -- and being -- you.