The engine noise that comes and goes is still a noise. Small problems you ignore often don’t stay small.

Something that only happens sometimes is still happening. Intermittent trouble is easy to wave off because the quiet stretches feel like proof it sorted itself out, when really the conditions just moved. Most expensive problems had a cheap version first, and the cheap version was the ignorable one.

Make a note the next time something glitches and then goes away, whether it is a car, a knee or a laptop. Write down when it happened and what you were doing. Two entries in a row is a pattern worth showing somebody.