I am wondering what standard phrase or idiom expresses that one's skill or talent in a particular area has not decayed through the passage of time.
I believe a related idiom is, "[the person] has not skipped a beat", but I have a strange feeling that this is not the "standard" English expression for this use case. Indeed, I suppose "skipped a beat" does not express the time component above, merely that the person's ability is flawless.
Example sentence: Lieutenant Columbo is a real sleuth. Despite his advancing years, he never skips a beat.