A rule change can turn yesterday’s expertise into today’s bad habit.

When a rule changes, the deepest expertise becomes the strongest habit to unlearn. The player who mastered the old game has more to undo than the beginner has to learn, and their skill becomes a liability precisely because it runs below conscious thought. Depth of practice is what makes adaptation hard.

Expect this in your own field whenever the conditions shift. The parts of your competence that feel most automatic are the ones to examine first. And be careful about dismissing newcomers who are doing things wrong by your standards, since some of the time their standard is the one that now applies.