Why do battery and software faults beat me, when engines never did?

You built your instincts by hand. You could hear a bad bearing, feel a loose wire, see wear before it became failure. That took years, and it worked, because the fault lived in a part you could touch. Batteries and software do not work that way. The fault lives in a trend over time, or in a line of logic that made sense to whoever wrote it and to no one else. There is nothing to put your hands on. Your old method is not failing you out of weakness — it is simply the wrong tool held against the wrong lock. This is not a sign you are behind. It is a sign you need a second instinct, built the same patient way you built the first one: by tracing real cases, logging what you see, and learning to read data the way you once learned to read sound.